Wil Wheaton is a weird character. Some of this acting I find bad, but some are incredible natural (compare his early Wesley Crusher acting with his late The Guild acting. Also, assorted Big Bang Theory episodes).
On the other hand, writing seems to be his strongest point -- something that we reckons himself in this book.
In "Just a Geek", Wheaton collects some of his blog posts from wilwheaton.net and tells the story behind them. In a way, it's the reverse of Ghost Rider: Travels on the Healing Road: Instead of telling what was happening with hidden emotions and then telling the truth in other media (in "Ghost Rider", it's Neil letters), here Wheaton sounds like everything is going fine in the blog posts -- at least, in the first ones -- and tells what was wrong in the book itself.
I feel like an idiot describing this, because it sounds too much like some marketing/paid content, but the book goes from the child actor in Star Trek: The Next Generation era to his internet celebrity point (although it doesn't go into the internet-video era, with The Guild) and Wheaton admits all his errors and how he "found himself" (anyone who had to go through this road can related to his story).
It's nice to read, even to get some idea behind TNG. It's direct, with Wheaton telling every time he got pissed with himself. And, in the end, it's a very well written book, although there is a lot of content coming from other sources.