Your Spaces and Groups
For non-public wiki spaces, access is generally determined by your membership in a group or groups assocated with the space. You can see a list of groups you belong to on your 'Preferences' page.
If you find that you don't have access to a space that you think you should have access to, or if you find that within a space you cannot perform a function you think you should be able to perform, click on the 'Update My Memberships' link. Doing so will refresh your group list. If you still don't have access or the right level of access to the space, contact the wiki administrators at confluence-hq@mit.edu.
Using the Wiki
Vendor's User Guide (note that our installation has some configuration and other differences)