Get to 34, do Scarlet Monestary. If you want silk, that is the place to go. You'll have more silk than you can use. Plus there are tons of great drops there and great experience. SM was my favorite instance. You can get to level 40 there pretty easily.

Before 34, go to Stranglethorn Vale, do quests there, PVP, grind the trolls, stuff like that.

BTW, what character class are you?