Guild wars is notable for having the best user created support site I have ever come across. It is called Guildwiki and you can try it out here. The site is absolutely encyclopaedic. It covers every quest, every character, every location, every skill, every item and just about every blade of grass in the game. Unlike many wiki's it is extremely well edited and easy to navigate. In fact it is so good it has come to dominate all other Guild Wars reference sites and I doubt if there is a Guild wars player out there who doesn't use it. Here is a sample article listing the skills available to a warrior character. Here is a sample mission walkthrough. This one site has all the information you need to play and enjoy this game.
Othe rgames have support sites. There is a wiki for World of Warcraft for example. When I was playing WOW it was not very complete and it was poorly edited. It seems to have gotten a lot more content since but just look at a sample wowwiki page and tell me honestly it doesn't give you a headache. To the best of my knowledge the site most WOWers use is called Thottbot. Thottbott is certainly comprehensive but it is also a complete and utter mess. I think this sample Thottbot page speaks for itself.
The reason for my eulogising about Guildwiki is that Arenanet, the makers of Guild Wars, have just set up their own official wiki in apparent competition to Guildwiki. To be fair to Arenanet their reasons for doing this appear laudible. Guildwiki is run and paid for by one person. Often the servers cannot cope with the load and the site is slow. The offical Guildwars wiki promises better servers and a more permanent arrangement. Arenanet say they have been in contact with the creator of Guildwiki but they give reasons why they could not just buy the original site or even sponsor it. Apparently there is something of a legal quagmire about who actualy owns the contents of a wiki site.
I have fears that this may spark a battle of the wiki's with everybody losing out but I do hope that it all turns out for the best. I also hope that Gravewit, the creator of the original Guildwiki gets his just deserts for creating such a superb resource. I believe he is creating wiki sites for other games with the intention of making money from on-site advertising. If these sites are anything like as good as Guildwiki then I strongly reccommend people use them.