Most beneficial tradeskill for a Rogue?Follow

skinning/leather: You can make your own armor, but you have to proactively level it or you'll end up at level 45 making level 30ish gear.

Herb/Alch: You can make your own healing potions. Same as above you have to keep is capped to produce anything useful.

It entirely depends on how you want to play and what you want to pay out for.

If you want to make cash do skinning/herb or mining/herb etc.

Hope this was helpful.

My rogue has herb/skinning. I usually just find a guildy to make me any leather goods that I might need via my own skins and other misc mats. Herbs sell well and bring in a decent amount of gold that I use to buy whatever else I need. The statement about using LW is very true. You're going to need to really keep on it to produce anything useful for yourself. I find it easier to just farm the mats and find a guildy or someone in trade and give them a tip to make it - remember always tip crafters :)

My 60 hunter has engineering/mining and I will tell you that engineering is a lot of fun. I personally went goblin but if I could do it again I would go gnomish for the gadgets. There is a lot of decent stuff for PvE and PvP. Pluss you can make some cash selling ammo and scopes in your spare time.