Guild Wars 2

I haven’t played the game for quite a long time (a year)…….I wonder what being change while I’m gone….stuffs got nerfed, ways of making gold, etc.
Can anybody give me updates on these stuffs ? What do I NEED to know ?

Thank you in advance.

Your best bet is to read the patch notes:
http://wiki.guildwars2.com/wiki/Game_updates

There have been a lot of changes sense release, read the forums for specific areas WvW, PvP, events, characters, etc. and check out some of the 3rd party GW2 websites.

TP buy/sell
http://www.guildwarstrade.com/

Event guides
http://dulfy.net/category/gw2/

Guides
http://www.gw2wiz.com/