Here are links to things which I find interesting, and to people I
admire (or at the very least, to people whose web design I admire):
People: Ryan Moore taught me most of what I now know. Gabe Doyle may try to seduce you with his flashier web design, but do not be taken in so easily. George Pfau could have served the mathematical community well, for he can draw a circle better than anyone. Sadly, it was not meant to be.
Sandy Lane will give you the low down on what to watch. And more importantly, what not to watch. (That's all for now - I am not too popular)
Math related: Math Goes Pop - Ruminations on the perception of all things mathematics in popular media and culture. UCLA Math homepage - of particular interest to some may be the old qualifying exams. Princeton Math homepage Millenium Prize Problems - for those with much ambition, or those who don't believe a lucrative career can be had in mathematics. Planetmath.org - a decent online math resource MathWorld - another decent online math resource Wikipedia - a generally decent online resource which contains, among other things, math
Humor, et al: Finite Simple Group (of order 2) - This serves as a good transitionary link, as it both involves math and humor (at least, if you think math jokes are funny). What is a Mathematician? - For those of you wondering just what exactly it is to be a mathematician. explodingdog - I hate tetris, among other examples of quiet brilliance. ColbertNation.com bitterfilms.com - don hertzfeldt is amazing.