
1) Smith's Introduction to Godel's Theorems http://www.logicmatters.net/igt/ is a great book, with all the mathematics but willing to go into the philosophy.
2) Franzen's Gödel's Theorem: An Incomplete Guide to Its Use and Abuse http://www.ams.org/notices/200703/rev-raatikainen.pdf is enlightening in a different way.
I'll also mention a favorite author around here http://www.scottaaronson.com/blog/?p=710 .
http://www.logicmatters.net/2012/05/teach-yourself-logic-1-f...
Then get Smith's book An Introduction to Gödel's Theorems. It explains Gödel's results in great detail and doesn't assume too much background knowledge. A certain amount of perseverance will, of course, be required…
There's some supplementary material on his website: http://www.logicmatters.net/igt/
I read Godel's Proof after though, and I agree that it is a far clearer introduction to Godel's theorems.