How Do I Edit Pages?
On your left hand side there should be a "Wiki Navigation". Under that navigation there should be a link that says "Page Information" Go Ahead and hover your mouse pointer over that link and a sub menu will come up that will allow you to Edit The Page as well as view other information.
My Edit Box Is Too Small
Go to Special:Preferences and click On "Editting" Tab. Change the Rows and Columns to a larger number that would fill your screen resolution.