
Textbooks I still have:
- Operating Systems, Tannenbaum
- MINIX, Tannenbaum
- Computer Networks, Tannenbaum
Not schoolbooks:
- UNIX & Linux System Administrator Handbook
- The Linux Programming Interface
- Time Management for System Administrators, Limoncelli
- The Practice of System and Network Management, Limocelli et al.
NonCS:
- Statistics, Freedman
- MLA Handbook
- Technical Communication, Markel
As for written communication, Markel's Technical Communication was used in my English class in college and I remember getting a lot out of following its directions. As you might expect, it's very well written. Of course, I had the advantage of classroom instruction, but I think it would be helpful even for self-study.