I wish there is some easy way to learn Telugu. There are several books, but the downside is that you will learn the typical "bookish" Telugu and not the one used in day-to-day speech. However, here is my two-fold suggestion.
1. Buy a book - Rapidex sells a book to learn Telugu (English to Telugu). I know there are books to learn Telugu from Hindi too. This will at least get you started.
2. Start talking to people in Telugu (using the sentences you learned from the book). People may smile, laugh and try to correct you (initially), but it should not bother you because you are learning. If you continue regardless of who laughs etc, eventually (in a short time), you will be comfortably conversing in Telugu and become better day by day.
Telugu is my mother tongue and I absolutely love the language. I can also speak English, Hindi and Tamil as a native. So, if you would like me to help you with learning spoken Telugu aspect of it, contact me on my email (Som.Gollakota@gmail.com) and we can take it from there.
All the best.
-Som G