Finding Linux-able hardware information
First of all, I follow LinuxHardware.org, which posts news and article links related to Linux hardware. It's a Slashdot-like site, and you may also consider Slashdot's Linux section, although there is a lot more noise there (often very entertaining noise, to be fair).
LinuxHardware.net is a complementary site, essentially a search engine for external resources relating to Linux/hardware issues.
It's always worth referring to the Linux Hardware Compatibility HOWTO. It's not as rapidly updated as more specialized resources, but it's still a good bedrock resource for finding and working with Linux-friendly hardware.
Laptop users have an especially useful resource: Linux on Laptops. This is a compendium of user-submitted HOWTOs for a specific Laptop model and Linux distribution.
Also of use is the Linux tested site, which includes nice charts organized by hardware category and distribution, and Linux Online's list of Linux-friendly harware vendors.
Of peripheral (no pun intended) interest is Linuxdevices.com, which covers the amazingly rich world of embedded Linux. It offers news on embedded Linux phones, PDAs, digital cameras and camcorders, routers, and more. It also has news and resources for embedded Linux developers.