Here you can download Guru Charitra in Telugu in PDF format. Guru Charitra, also known as Datta Charitra or Shirdi Sai Charitra is the most famous book dedicated to Lord Dattatreya and Shirdi Sai Baba.
Some devotees recite this sacred book everyday and some may read this during special festivals like Guru Purnima.
Original Guru Charitra is written by L.R. Pangarkar in Marathi. According to him, two incarnations of Sri Dattatreya were incarnated in 14th and 15rh centuries (Sripada Sri Vallabha in Pithapuram of Andhra Pradesh and Sri Nrusimbha Saraswati in Deval Gangapur Sangam in Karanataka).
You can download chapter by chapter Telugu Guru Charitra PDF format here by clicking this link.