I use MTGSalvation.com for any news. I'm not sure about the rest, but they have an active forum. I tend to build decks without much outside influence, which is probably why I only play casual.
If you still have some of those 3rd/4th/Ice Age cards, you might have some that could fetch a hefty price.
Also, since you haven't played in a long time, you'll have to catch up on the rules. It's not a flat "here's the rules" site, but this blog is cool because they explain things in detail.
http://blogs.magicjudges.org/rulestips/