Specifications, manuals and manufacturer support often are not helpful. Therefore you should retrieve information from other sources too:
Highly recommended is the survey by Kenneth E. Harker http://www.cs.utexas.edu/users/kharker/linux-laptop/ .
Hardware-HOWTO
open hardware - The Open Hardware Certification Program The Open Hardware Certification Program
HARDWARE.doa.org - dedicated to the hardware aspects of (Linux) computing http://hardware.doa.org/
How to Build a PC FAQ - excellent hardware overview by Billy Newsom http://www.motherboards.org/build.html
Last but not least the WWW itself.