Below are some links to webpages that might be of interest to you. (If you know other websites that you think should be linked here, please let me know!) Related materials: Jeremy Avigad's excellent lecture notes on Computability and Incompleteness, and Logic and Computation. Professor Peter Suber's course Logical Systems covers similar ground as does our course. He has extensive notes on topics such as mathematical induction, non-standard logics, and A crash course on the mathematics of infinite sets, which you might find interesting. See also his article on the Löwenheim-Skolem Theorem (including Skolem's Paradox). The Standford Encyclopedia of Philosophy has very well-written and comprehensive articles about logic and philosophers we've heard about in this course. Historical texts: The Mathematical Problems of David Hilbert. Contains a link to an English translation of Hilbert's 1900 address in which he formulated his famous 23 problems, as well as to other interesting articles regarding the problems. Gödel's famous 1931 paper "On formally undecidable propositions of Principia Mathematica and related systems I". A modernized version can be downloaded from here. For more on Gödel, check out the April 2006 edition of the Notices of the American Mathematical Society. This edition of the Notices of the American Mathematical Society (Vol. 53, No. 10, November 2006) is entirely devoted to articles on Turing. [Thanks to Phil for the reference.] Have a look at The FOM Archives if you want to know what logicians and experts on the foundations of mathematics talk about these days. See who are the Mathematicians of the Day. LaTeX: LaTeX - A document preparation system LaTeX for Logicians (introduction, packages, etc.: all you need, and more!) The Comprehensive TeX Archive Network (CTAN) is the authoritative collection of materials related to the TeX typesetting system. FAQ (in French).

See also his article on the Löwenheim-Skolem Theorem (including Skolem's Paradox).