For a first-time player of Bioshock, I generally wouldn't recommend a game guide like this. For me, the game is about exploration - you are supposed to be lost and find your way around. but Bioshock is not just another FPS. As well as being incredibly well done - involving story, beautiful scenery, challenging monsters, etc, it has a great depth, augmented really by the Xbox Achievements system. Thus while you can play through some games once and get to do pretty much all you could want to (Halo 3, I'm looking at you) it is quite possible to go play through Bioshock and miss quite a bit, including an alternate ending.
some of the achievements are actually quite challenging - 'access every single tonic in the game' or 'listen to every audio diary' for examples pretty much require you to see 100% of the game's content. And doing that would be pretty challenging without a guide like this.
The guide is as in-depth as Bioshock itself (no pun intended) and tells you where absolutely every tonic, plasmid, vendor and U-Invent is. It uses the same style of map as the game itself, but improved of course by showing you all the hidden stuff. There is a walkthrough for every level as well which, if you follow it, will allow you to collect every available piece of gear too.
So, if you're looking for a perfect 100 gamerpoints, I highly recommend this guide.