S-GRAFIKZ

Anthony Zinni made a link collection to more than thirty PDF documents every designer should download. They all contain information that no designer should go without!
There are 10 of them that i liked very much:

1) AIGA Why Design? Booklet

2) Getting Real – 37signals (Read Online for Free)

3) DotMobi Mobile Web Developer’s Guide

4) Accessibility Checklist – Aaron Cannon

5) Dive Into Accessibility

6) Grids are Good – Khoi Vinh & Mark Boulton

7) Elegant Web Typography – Jeff Croft

8) Web Designer’s Success Guide

9) Introduction to Good Usability – Peter Pixel

0) Time Management for Creative People – Mark McGuinness

Here you can get the full list to more than thirty very usefull links.