I don't know of any books (they don't have Afrikaans books in the USA really) BUT there is a free website that does a very thorough job. It was made by a native speaker of Afrikaans that now teaches the language.
It's on http://www.openlanguages.net/afrikaans and there are even little recordings of how the alphabet sounds.... Every word and phrase it teaches you has a voice recording so you can hear what it's supposed to sound like. It's better than trying to use Rosetta Stone or the like, in my opinion.
