I've become a little obsessed with type. Type carries a massive amount of information sharing potential. In addition to the text it carries, the type itself is a potent tool for talking to your user, establishing information hierarchies, creating a mood, establishing order, etc. It's a tool you, as a UI guy, want to keep sharp.
So, here are some of top-of-mind resources that I've stumbled upon.
Helvetica (the film)
Start here. This is a fun movie for anyone who can appreciate a geeky obsession of any sort and it's also a great way to kick off your new found type interest. You'll finish it saying the word "typeface" in a lot of situations where you used to say "font." You'll also realize that type designers have managed to keep a lot of old world charm in their always up and coming craft.
Pad your fonts folder with this incredible list of really beautiful (and free!) fonts from Smashing Magazine (another great place to find some good information about type).
In fairness I have only ordered (not received or read) these books, but they come from a reliable source and were billed as "quick reads": First, A Life in Typography by Ruari McLean and, second, Designing Type by Karen Cheng.
Last of all, some slightly more esoteric links are: The Penguin Paperback Spotters' Guild and the International Typographic Style group, both on Flickr and on Wikipedia (here and here). And of course the requisite catch-all: someone else's much more comprehensive list of type resources can be found here.