Yes, there is a book that used to cost 350 dalasi, when that was a lot of money, and I bought it, but it is not entirely correct and the lingo of some upriver village, a Peace Corps publication. I think now it is available for free download on the internet. Do a search on google, you will certainly learn something out of it. Hard to pronounce though without hearing it, I did find some basic Mandinka lessons with sound bites so you can listen. I have no idea where I found it or the web address, I was a bit beyond it by then, but I suggest again to google it and I am sure you will find it. it definitely exists. It is a great idea to learn some mandinka, it is fun and a lovely language. People appreciate you making the effort even if you are not much good at it, and you will be better equipped. And you will be able to sing along at programmes!