EDUs enjoy really good treatment from the search engines, so long as they police their sites for spam.
Building links is important, just as inbound pointed out. Students and alumni typically love their universities, so it's easy to build off of that. Provide a "link to us" page which provides html code to allow your fans to copy and paste the university logo icon onto their personal homepages, linked back to you. Use beneficial/relevant keywords in the ALT text of the logo to drive a bit of keyword weighting to your site. Ex:
alt="Harvard University, Cambridge Massachusetts"
All the basic SEO factors can be employed by university/education sites, and should be to provide a firm foundation for more advanced methods.
As for directory submissions, most educational institutions are already listed in internet yellow pages and other local directory types of sites. However, some of those directories allow "captions" or sub-listings for large institutions like colleges and hospitals. Beyond your basic listing, you might be able to get a phone number, address and hyperlink back to your site for every department or office in your institution -- a method that generates more links back to you than a standard directory submission. This capability depends on each individual directory's rules.