This might be heresy on a PC forum but have a look at the Mac notebooks - it's one way of getting round the myriad of specs offered by the PC manufacturers.
If you bought a Powerbook (nippier processors than the iBook) and upgraded from the basic spec to a gig of Ram, Bluetooth and Airport Extreme you'd have a very capable notebook with storming battery life (my iBook lasts for nearly five hours).
In answer to your questions, Bluetooth is an under-rated wireless technology that has been somewhat eclipsed by wi-fi. Bluetooth is great for ad-hoc wireless connections between devices like PDAs, mobiles and computers (both PC and Mac). Windows XP with SP2 supports Bluetooth better than any previous iterations of Windows, though you'll need a dongle (looks like a USB flash drive). I use a Bluetooth dongle with my iBook and it just works - no drivers to install, nice intuitive software. You can also use Bluetooth to do away with the cable between your PC/notebook/PDA and a Bluetooth-enabled printer.
Wi-fi is an increasingly popular method of wireless networking, mainly used to share a broadband connection. With the right kit - modem/wireless router and Wifi receiver (either internal or a dongle or, in a notebook, PC card) it should in theory be pretty painless to set up, though you don't really need it at home if you've just got the one machine. If you're thinking about sharing an internet connection, though, it's invaluable.
Again, I find it much easier on the Mac notebook: again, it just works, there's very little fussing about with obscure stuff like IP addresses.
Finally, do buy a widescreen notebook if you're going to play games (there are quite a few available for the Mac and you're less likely to find it choking on a new game as the hardware upgrade cycle is longer with Macs) or watch DVDs; otherwise I'd stick with a smaller, lighter notebook - especially if you're planning to travel with it.
I'm sure others will have buying advice too - enjoy sifting through it and come back if you have any further questions.