Click on "advanced search", underneath the main search box, to narrow down your search by item type, such as thesis or DVD.
You can sign in to your library catalog account to renew your books, place holds, create lists, etc., using the link in the far upper right. Contact the library for help with your login information.
If you're looking for journal articles or other electronic sources, you'll want the databases. The link is on the left hand side of the screen. You can also visit the library's main research portal for tutorials, library news, etc.