I'll be gentle since it's your first post ;) If there is no thread about it, it's because it's just so obvious. The information is everywhere. Like on Wowwiki for instance: http://www.wowwiki.com/Dual_wield
Before asking something, please try to find it all by yourself 3 min. Googling "wow rogue dual wield" instantly leads you to dozens of web sites that answer this very question.
This will help keep the board filled with interesting threads discussing advanced elements of the game which are not (or not that easily) found elsewhere.
Thanks.
nostra