Shadow Warrior Advice

[ArchedTurtle]

Ive just started playing this game and am just wondering if anyone has any tips to playing a good shadow warrior, best trees to spec into, best skills to use, rotations etc..

[Mystry]

There's a guide in the High Elves forum that is (mostly) accurate.
To sum up in an extremely brief way, you have a choice between skirmish and assault (scout isn't really viable yet but recent changes have shook it up, and we might see a good scout build emerging soon).
With skirmish, you load up your dots (particularly your spammable healing debuff) then plink away at the enemy with spiral fletched arrow (I think that's what it's called - the one that you shoot while moving in skirmish stance). It's entirely single target and has less burst than assault, but is safer from the melee train since you are ranged and have whirling pin and kiting moves to stay out of melee range.
Assault revolves around a short period of extreme burst where you dart in to melee combat and frontload a bunch of damage on one target. Load up on dots (including healing debuff), then approach the target, use Vengeance, knockdown them and spam grim assault.
More detail is available in the SW guide on the High Elves sub-forum.