X-Men
Ahhh, the X-Men. Aside from the quasi-porno name, this family of comics produces some of the best selling titles in the world. The whole "mutant" issues have incredible and obvious parallels with civil rights, women's rights, and gay rights movements. The stories are well written and capture the readers attention with ease. Once you start reading one of these serieses, you won't want to stop.
Marvel.com
Just to let those *LOVELY* people at Marvel know I'm not putting the stuff that's here up for profit, here's a link to their site. This is their section on the xmen specifically, so check it out. Take a peak and check out the part about the movie!
Wolverine's R.E.A.L.M.
This is a really awesome site on the fiercest, wickedest, and from what I've read in Wizard, most popular character in all of comics, Wolverine. He kicks stuff. Oisii desu ne? ;) Check out the fanart section, there's some really good stuff there, not to mention that it has to be one of the biggest compilations you're going to find on the web.
X-Archive
Well. Uhm.. if you know a lot about the X-Men, and you want an... "interesting" site, this is the place to go. It's what a few of my friends would call, "Special", but its definately worth checking out if you're really into the X-Men. If you don't get all the subtext I'm putting into this description, then you need more help that can be given by a website. ^_^ Enjoy!