Its the WTO website. Under the 'The WTO' heading on the top banner there is a link that has all info on what the WTO is, what they do and info on the member countries. Your textbook should also have some brief background info on the WTO too.
Umm the wto also has the role of resolving trade disputes that occur through their dispute resolution process! and attempting to break down trade barriers (trade liberilisation)...ahh what you have is right, but its preety broad. Maybe a good opening sentence to a short answer qn, but youd have to expand on it if its worth anything significant.