Get Bradt's Guide to Madagascar - http://www.amazon.co.uk/Madagascar-10-Bradt-Travel-Guides/dp/1841623415/ref=sr_1_2?s=books&ie=UTF8&qid=1371657347&sr=1-2&keywords=madagascar - and study that.
I haven't been to Madasgascar personally, but I do know the author of this book, and I know she has...