Here's a better picture; a screenshot from Amazon.com's website (there's a link to this below).
The artwork looks strangely familiar to me... Something like Looking for Group...
There's no mention of Lar DeSouza working on the artwork for this book on Amazon.com, and they've got a fair bit of material from inside the book on Amazon (check it out) including the inside of the cover, the back cover, index and table of contents. No mention of these characters that look exactly like Lar's artwork. So, I messaged Lar and Sohmer on their forum and asked if they knew about it, since it's distributed both in the United States and Canada. I probably should have bought Lar and Sohmer a copy and sent it to them, but that would probably be a very bad way to inform them of this if their work (mainly Lar's artwork) was stolen.
So that first picture has characters that look strangely like Richard and Krunch from the webcomic, who also could be generic looking characters from World of Warcraft if you designed your characters on the game to look like them. Benny and Pella (or in this case, Pella's twin brother) have no analogies in WoW so far as I know, especially Benny.
If Lar and Sohmer knew nothing of this book being printed and sold with their work on the front cover, I can imagine them to be way more pissed than I am right now.
Update: This is legitimate. Lar drew the picture for their book. Everything is good.