See the uPortal Manual. The wiki also contains information related to how to deploy uPortal, customize it for your institution, and develop content for it.
There are other places where information about uPortal can be found that can be especially useful if you are having trouble with uPortal. The uPortal mailing lists are valuable resources for answering any questions you may have. Jasig also maintains a robust Jira issue tracking system for tracking bugs, enhancement requests, and maintaining release notes.
For more support information, see our uPortal community page.