Bureacracy. Ask people what the procedure is for buying a work-related book. Assuming that the answer isn't "we can't buy books" (bzzzt!), ask what the procedure is for being reimbursed. It's not uncommon to in Silicon Valley to have a "if you need it, go buy it and submit and expense report" or "ask me first" policy, but some places go overboard in how much time and expenese they'll incur to basically tell you "no". If a company is going to burn through an hour of administrative time to tell you that you can't spend $40 on a book that might save you 10 hours of work, they're being stupid. Life is too short to work for needlessly stupid companies.

Lighting. As your eyes get older, the effect of florescent lights + basic, low-refresh rate monitors becomes harder to live with. If you're starting to have problems, make sure you won't be living in a veal-farm of cubicles, with no direct outside light, and no way to turn off the florescents. Life is too short to go home with eyestrain headaches every day.