There are quite a few good books out there. I've personally enjoyed reading about the history of the fraternity (Gridley's "The Freemasons," or Stevenson's "Origins of Freemasonry" for example).
Honestly, I think I've learned more from preparing Masonic Education presentations for Lodge than via most other routes. We previously just had someone read a Short Talk Bulletin and call it good. This last week, I presented on "Why the Saints John" and managed to include a discussion on the symbol of the point within a circle with two lines running tangent to the circle and parallel to each other.
I would look at the tracing boards for the various degrees and pick something of interest to research. Ask the WM if he would mind you presenting something on it at the next meeting. Pike's Esoterika has quite a few interesting bits on the 3 degrees, and also includes early exposures, so you can see how some groups of Masons performed the rituals in the early to mid 1700's.
Either way, anything is better than nothing. The first books I picked up were the Mackey Encyclopedias. I found a cheap set on eBay. If you can find the Little Masonic Library, that's a wealth of knowledge in a compact set.
Best of luck, brother!
Edit: The ritual of Freemasonry is very thick with meaning, and I personally have learned quite a bit by comparing other rituals to ours, as other systems might explain things differently. If you have a chance, the Emulation ritual from England is an interesting place to start. Discussing the cable tow and reception of the candidate in Emulation, it's made very clear that the implements involved were lethal in capability. Food for thought, and a great discussion starter in Lodge.