I definitely agree with Cuilan. Everything still works, there just aren't as many active people. Find an active guild and alliance and you are sure to have a blast.
If you need reference material about quests, builds, or just guild wars in general, here are some good sites to use.
http://wiki.guildwars.com/wiki/Main_Page -- A general wiki of everything.
http://gwpvx.gamepedia.com/PvX_wiki -- A decent database of quality skill sets, try not to rely on it too much though.
And of course, gwguru, for all your specific questions.