The stories about Sai Baba (born 1835-1840?, d. 1918) are retold from the book The Incredible Sai Baba by Arthur Osborne (1972). Page references are put in brackets, and the book data is given at bottom.
NOBODY at Shirdi knew Sai Baba's birth name, and practically nothing was known about his early years. 
He lived in a half-ruined mosque and did not teach any specific means for God-realization. He could not be persuaded to live anywhere else. 
He acted in symbolic ways, worked miracles, and spoke in parables all along.
Sai Baba used to spend much of his time grinding wheat into flour. He also kept mud pots. [76-77]
He became a growing power for good.
SAI BABA did not need to go into samadhi in order to achieve anything or to attain any higher status or knowledge. 
All his life Sai Baba kept with him a common brick that his Guru had given him. When it dropped and broke in 1918, he said that now his karma was broken, and "I shall not survive its breaking." 
Sai Baba's fame began to spread about 1900. 
NO ONE knew who he was. He had first appeared in the little town of Shirdi as a lad of about sixteen in 1872 [some say 1854 and 1856], as wandering fakirs do, none knowing from where or why. He wandered away again, roamed about for a while, and then came back and spent the rest of his life there. During his earlier visits he lived under a neem-tree, sitting there in the daytime, sleeping on the bare ground at night, eating what little food the charitable townsfolk gave him. 
When at last he settled down in Shirdi, the custodian of the Hindu temple there refused him admission, bidding him go to the mosque to live. He did so, and the little mosque remained his home. [cf. 11]
He spoke with the holy men, Hindu or Muslim, who occasionally passed through the town, and one of them had told the townsfolk: "Watch that young fakir; he's a jewel . . ." But they did not take much notice - not at first. 
Shortly after Sai Baba's passing, Swami B. V. Narasimhaswami made a collection of his sayings and anecdotes about him. The Swami asked Arthur Osborne to make full use of all the publications of the Samaj. 
Shirdi Sai Baba was an Indian guru, yogi and fakir. The name 'Sai Baba' is a combination of Persian and Indian origin. Sai is Persian for holy, and baba means father in Indian languages. Thus, "holy father".
Sai Baba taught devotion to God and guru. His philosophy was Advaita Vedanta. He led an ascetic life, at times sitting motionless under a neem tree and meditating. For four to five years he lived under a neem tree, and often wandered for long periods in the jungle.
After 1910 his fame began to spread in Mumbai. Sai Baba left behind no spiritual heirs and appointed no disciples. He did not even provide formal initiation. Some disciples of Sai Baba achieved fame as spiritual figures like Meher Mahasaya.
In his personal practice, Sai Baba shunned any kind of regular rituals but allowed the practice of namaz, chanting of Al-Fatiha, and Qur'an readings at Muslim festival times. He was an opponent of religious orthodoxy - both Hindu and Muslim.
Although Sai Baba himself led the life of an ascetic, he advised his followers to lead an ordinary family life. He encouraged his devotees to read some holy scriptures such as the Ramayana, Bhagavad Gita, and Yoga Vasistha. He advised his devotees and followers to lead a moral life, help others, treat them with love and develop good faith and patience. He criticised atheism, and also interpreted the religious texts of Islam and Hinduism. He explained the meaning of the Hindu scriptures in the spirit of Advaita Vedanta.
Sai Baba said that God penetrates everything and lives in its essence somehow - and that the Lord's gifts are eternal. He advised his disciples and followers to overcome negative features of character and develop the good ones. His teachings were oral, typically short, pithy sayings. He encouraged charity and the importance of sharing with others and of due, common-sense respect."If anybody wants any money from you and you are not inclined to give, do not give, but do not bark at him like a dog."
Sai Baba made eleven assurances. From three of them: "My mortal remains will speak from my tomb. If you seek my advice and help, it shall be given to you. There shall be no want in the house of my devotee."
Sai Baba's millions of disciples, followers and devotees believe that he had performed many miracles. The most important source about Sai's life is the Shri Sai Satcharita written in Marathi, in 1916 by Govindrao Ragulnath Dabholkar (translated into English by Nagesh Vasudevanand Gunaji with English title: Shri Sai Satcharitra)
In Sai Baba temples, his devotees play various kinds of devotional religious music, such as aarti.
Sai Baba used to go to the shopkeepers in the village to beg oil for them lamps in the mosque. One shopkeeper nudged the other, "Let's have some fun with him; let's refuse to give him any oil."
Refused oil, the young fakir turned and went back with no word of complaint or beseeching.
"Let's follow him back and see what he'll do," someone suggested.
Back at the mosque, the fakir picked up a mud pot of water that stood there and filled the lamps from it and they burned as with oil. In sudden awe the onlookers fell at his feet and begged him not to curse them for what they had done. And they soon found he was compassionate. [12-13]
Example of the profundity of Sai Baba and the symbolism of his speech [cf. 31]
"Once I was arguing with three friends how to attain Self-realization.
One said the Bhagavad Gita says "Raise yourself."
The second said, "Keep the mind free from thought."
The third said we would have to discern constantly between the Eternal and the transitory.
The fourth said, "Let us surrender to a Guru in faith."
As they roamed through the forest they met a labourer who warned them that they should get lost in the trackless thickets, and invited them to stay and share his food. But they rejected his offer and advice and walked on, only to lose their way in the vast, dense forest.
The labourer met them a second time and invited them to share his food, but the same think happened. But as the four continued on their way, one of them felt hungry and went back and accepted a piece of bread from the labourer and drank some water.
Then the Guru appeared. I bowed down to him reverently. He took me to a well, tied my legs with a rope, and suspended me head downwards from a tree that was growing beside it. My head was about a metre above the water, so that I could not touch it. My Guru returned four or five hours later and asked me how I was getting on. I answered that I had passed my time in great bliss. He was delighted with me and embraced me, passing his hand over my head and body. He made me his disciple.
I loved to gaze on him. I had no eyes except for him. I did not want to go back." [14-16]
"The whole story is symbolical." - Arthur Osborne. 
A Brahmin doctor was once taken to Shirdi but warned his companion that he would not bow down to Sai Baba, since he worshipped Sri Rama and no other. He stood outside the mosque, watching the Hindu ritual that was being performed inside, and then suddenly he rushed in and fell at Sai Baba's feet. When asked later what had made him change his mind he said that he saw Sai Baba standing there in the form of Rama. [41-42
Westernized, educated, urbanized India is captivated by Western ideals of science and progress . . . and is very sensitive about being thought backward or superstitious. It is the products of this India who write books for foreign publishers and overseas sale . . . they shrink from proclaiming a saint who taught in miracles instead of books. 
"Sai Baba's benevolent compassion evoked deep reverence." [A]
A thief was arrested with stolen jewellery and brought before the magistrate's court in the neighbouring town of Dhulia. He brought forward the plea that Sai Baba had given him the jewels. People around were aware that wealth was heaped on Sai Baba daily and disbursed or distributed by him the same day; but in this case the jewels were stolen property. A summons to Sai Baba was issued. He was to attend the magistrate's court.
"Take that rug of paper and chuck it in the fire, one of you!" Mahasaya roared.
Now a warrant was issued for his arrest. The constable who came with it, asked, "Will you please come to Dhulia with me?"
With a torrent of oaths, Mahasaya ordered him to throw the warrant into the latrine.
Next a good magistrate was sent to where Sai Baba lived instead, and routine questions were answered from another level -
When asked about his name, he said, "They call me Sai Baba." And he intimated he stood above the religions, and had followers on both paths, Hindus and Muslims.
"Will you swear that what you are going to say is the truth?"
"The truth," he affirmed.
"Do you know the accused?"
"Yes, I know him . . . I know everyone."
"Did you give him some jewels, as alleged by him?"
"Yes, I gave them to him . . . Who gives what? And to whom?"
"If you gave him the jewels how did you get possession of them?"
"Everything is mine."
The magistrate now lost his patience. "Mahasaya, this is a serious charge of theft. The man says that you delivered the jewels to him."
Mahasaya also lost patience. "What is all this about? What the devil have I to do with it?" And he strode away.
Not long after it was discovered that the accused had not been at Shirdi at the time of the theft. [31-35]
If one meditates on me, repeats my name and sings about my deeds – he is transformed and his karma is destroyed. I stay by his side always. - Sai Baba
I speak the truth. - Sai Baba
I am not the body or the senses – I am formless and in everything. - Sai Baba
If any . . . creatures come to you . . . receive them well and treat them with due respect. - Sai Baba
If anybody wants any money from you and you are not inclined to give, do not give, but do not bark at him like a dog. - Sai Baba
Calmly look at the show of all things passing before you. [Sai Baba modified. B]
Sai Baba's biographer Narasimha Swamiji writes that Sai Baba was born as the child of Brahmin parents:
Very late in his life, he revealed . . . that his parents were Brahmins of Patri in the Nizam's State. Patri is Taluk in Parbhani district, near Manwath. Sai Baba added . . . that while still a tender child his Brahmin parents handed him over to the care of a fakir who brought him up. [Narasimha Swamiji, Life of Sai Baba]