(edited by xBrokenSoulx.7069)
PvP Guardian tips
Unfortunately with the current state of the guardian class, in sPvP you’re going to have to choose to play either a tanky role or a DPS role. There isn’t a very efficient middle ground.
For a tanky build I’d recommend running a staff build with shouts and probably AH. For DPS, a burst meditation build featuring GS, sword, or scepter would probably be best.
http://metabattle.com/wiki/index.php?title=MetaBattle_Build_Wiki
This should help you out with builds, but as Black Box said, you either go dps or full bunker (to support your team).
Also, PvE stats and level have 0 effect on PvP. You can set everything by going to the Heart of the Mists and click the “PvP Build” button on the middle-top of your screen.
Watching top players also helps a lot but there aren’t really any active guard streamers. But you can watch streamers even if they play another class, because they often tell why did they make a given decision or they’ll highlight their team’s mistakes so you can learn a lot about the gamemode from that too.