This is just their reading list. You should checkout the forum and blog. And yes, those are affiliate links:

    $ curl -I http://personalmba.com/books/cut-to-the-chase/
    HTTP/1.1 301 Moved Permanently
    Date: Wed, 24 Dec 2008 19:26:49 GMT
    Server: LiteSpeed
    Connection: Keep-Alive
    Keep-Alive: timeout=5, max=100
    Location: http://www.amazon.com/gp/redirect.html?ie=UTF8&location=http%3A%2F %2Fwww.amazon.com%2Fdp%2F0385516207%2F&tag=personalmba-20&linkCode=ur2&camp=1789&creative=9325
    $

Considering how easy it is to get around the affiliate link (just search for the ISBN in a separate amazon/google window) OK, he should probably have put a little disclaimer somewhere about the affiliate program, but other than that, I don't really understand the "he's using affiliate links" drama. If you were to buy a book he suggested, why not let him be rewarded for suggesting it? You lose nothing, and he gets his work rewarded. If you disagree with this, just buy the book without following his link.

There's nothing wrong with using affiliate links. Hidden affiliate links have nothing to do with you or to fool you, it's to stop the search engine from punishing them which again, there is nothing wrong with.

He didn't hide the affiliation, he said so up front. Under each category is a mini-review of each book. That makes the site more useful than just a list of books.