I had the Sims 2 Prima guide and loved it, so didn't think twice about buying this one for the Sims 3. Sadly, it's nowhere near as useful as its predecessor! It reads more like a very long (and very positive) review than a guide book, and while this does make it nice to read, and the author comes across as very likeable, I don't feel I actually learned anything of use from the author raving on about how good the game is. Most of the information in the guide is easily picked up in the game (the tutorials are great), or is already common sense. Where the Sims 2 guide went into great detail about all sorts of aspects, this one just... didn't. I was expecting little tidbits that I wouldn't find anywhere else, but this was not the case. An example is that my boyfriend told me about being able to change your Sim's name at City Hall, a fact I had completely NO IDEA of after reading the guide cover-to-cover. Another thing that bothered me was the omission of some simple stuff, like information on getting a Sim to move in with you. Sure, it's pretty easy to figure out in-game, but then what's the guidebook for?
Also, there are a fair few errors in the text, where the wrong word has been used or words/phrases have been repeated. It feels like the guide didn't get proof-read, and wasn't quite ready for publication.
It's not ALL bad, however... the careers section is worth a read, and I found the table of traits for existing Sims useful. But all in all, I'd say you can get by just fine without this guide. I think I wasted my money to be honest.