If you're interested in Typography, I'd suggest reading "Stop stealing sheep and find out how type works"[1] by Eric Spiekermann. Great introduction to practical Typography!

[1] http://www.amazon.com/Stealing-Graphic-Design-Communication-...

Typography is a big topic, but a good introduction is "Stop Stealing Sheep and Find out How Type works" by Erik Spiekermann [1]

It is an especially good read for non-designers, though I've given several copies to interns.

[1] - http://www.amazon.com/Stealing-Edition-Graphic-Communication...