You can actually find films in the various catalogs much as you'd find books: search the catalog for a title, subject or filmmaker's name. The main difference is that you'd use various tools to limit to films or videos.
In the College's OneSearch tool, you can do this by selecting the Advanced Search option, then choosing either "ConnColl Books and Media" or "CTW Books and Media." Then, under "Material Type," select "Audio Visual."
If you're using Worldcat, just find the "Format" dropdown menu on the search page, and click "Visual Materials."
More information on how to search is available on the Searching for Articles and Books page.
If it turns out that you find a film that Connecticut College doesn't have and that isn't in the CTW consortium, you can always try placing an Interlibrary Loan (ILL) request for the item. Our ILL staff routinely fulfills requests for films/DVDs that we borrow from other libraries.
The library provides access to Kanopy, a database for streaming video that provides a very rich array of films that can be clipped, shared and posted to Moodle.
You can find numerous sites on the Web that feature film and television clips of varying lengths and kinds, including full-length features, news clips, television shows and ads, and archival footage. Here are a few links to some prominent sites; for more information on each one, hover your cursor over the link. For more suggestions, check out the library's Finding Multimedia research guide.