I just started developing on android. I used two books,
1- Hello Android :
This book is really nice when explaining how android applications run and how the system really handle your app, "BUT" it doesn't really explain Java and it assumes that you have somewhat experience with Java.
2- Beginning Android 2:
This book is meant to be for beginners in both java and android development.
I really recommend these two books in parallel. I got them online as an eBook. you'll save a lot this way. one of them is only $10 and the other one is $24.
If you buy the paper one they will cost $44 and $32.
If you want to get the discount on the eBooks buy the paper books go home, get online access the book website and look for the link for the discounted eBook for paper books owners. they will ask you a question like
"what's the first word on page XXX" or "which page is figure 3.6.1"
all you have to do is to look for the answers, put them in then buy the discounted eBook then finally return the paper books to the book store.
Good luck.