Levelling in WvW is fast. Especially if your group takes a lot of supply camps, keeps, etc.
You'll gain huge amounts of XP doing it. Doing a WvW event with GSCH typically gains a member around 4-6 levels per event, depending on how long you play for and what the intent of the WvW event is. If it is to karma train WvW, you're golden. If it is to actually play strategy and fight against the other server, you're still good but you won't level as much, because you'll spend more time defending and in combat.
Combine playing WvW with map clearing all of the different races home areas like "Divinity's Reach" ( Human's home area), and you'll be levelled up in no time with no risk of getting killed in one shot by NPCs. You can get to all races home areas through Lion's Arch.
Speeding through your toons personal story also gets you a lot of XP.
Then there's crafting. I know jack squat about crafting...beyond that it is the fastest, though most expensive way to level up.
As for choosing a profession for WvW, I suggest rolling a Guardian. WvW is all about team play, and if you are wanting to play with a team of GSCH in WvW, the Guardian is the ultimate team player profession. They are literally the "guardians" of the group. Pun intended. They are fast, powerful and hard to kill. They shake off conditions with ease, and are a total boon-fest. They better the survivability of those around them. My guardian was quick to level up by doing it the way I described. I levelled up my guardian almost exclusively in WvW. The only reason why my guardian went across Tyria, was to get to dungeons. Everyone LOVES guardians in dungeon runs.
» Edited on: 2014-03-11 16:14:21