Alright, it may be because I stayed up way to late doing t3fractals and so my mind isn't entirely here, but after searching the forums for a relevant helpful link thread I was unable to find one. So unless someone points to another location where I should add information I'm going to start one here. I will update the list if anyone wants to respond with stuff that they use just try and follow the format so I can throw it in the appropriate sections. (Yes, I know there's a helpful link sidebar, but this might be a little more information than what we want to put in there)
Guild Wars 2 Wiki - Official GW2 Wiki. Accessed in game with the /wiki <subject> command. Relatively accurate and up to date information about almost everything in game.
Dulfy.net - Dulfy's blog/site associated with Guild Wars 2, very informative in a lot of areas, I'll be linking specific parts of the site later on.
Item Nomenclature Wiki entry - Significant source of information on the wiki to stand out on it's own, helps familiarize yourself with the types of stat distributions (Beserker, Valkyrie, Knight, Rabid, etc) and where to obtain them.
Food Wiki Entry - Food! But seriously, food can be a significant factor in how you build/gear your character and it can also help supplement your playstyle dramatically. Check it out and eat food!
GW2 Crafts - Guides you from 0 to crafting hero in each profession.
GW2 Efficiency - Great tool for seeing what is in your account, but also has an excellent crafting calculator for gear.
Trading Post/Money Making:
GW2Spidy - Spidy is the endall site when it comes to market information in Guild Wars 2. Regularly scans the trading post for all orders and posts the data here linked with the GW2DB for easy reference. A specific item to note is the Crafting section of Spidy, lists out the profitability of each item/recipe within each crafting tradeskill.
Egg Baron's Skill Points to Gold - Direct Link. Gathering Information from GW2Spidy and using the upconvert recipes it calculates out the profitability of upgrading items using the skill point materials. Guide changes regularly via 15 minute intervals, helpful if you watch the market for knowing when to sell/upconvert or hold on to things.
GW2LFG - Pretty self explanatory, since dungeons can be run across servers this site allows people to post 'Looking for Group" posts to help people group up and run "Pick-up Group" dungeons better than faster.
World vs World:
GW2 Stats - Lists out the current WvW scores, and projects where each server will be the following week. Also has some pretty cool graphs and information.
Added it. I had the same problem with some stats freezing up, and it will be nice to save a build when it gets there. It's great that the stats of the Ascended items were added, but they need to include the pre-infused stuff as well if they are going to gauge AR. Anyway, good link thanks.
I would suggest that you include gw2lfg in the pvp part of this. Although it is very rarely used (partly because pug tourny's aren't very good usually and partly because a very small % of people do spvp from that i am aware) there are occasionally people that post on there about spvp.