One of the best ways to improve as a guitar player is by playing live with other musicians. Finding someone to jam with shouldn't be too hard, even for newbies.
Have you tried to post on college boards? There may be some amateur musicians in school that would be willing to jam. Another good resource is a music school that teaches guitar lessons, drum lessons, etc. Students are usually encouraged to play in some kind of ensemble, so jams can be arranged with them through teachers.
Being wary of unsavory types is always a concern, though most musicians tend to be pretty mellow. Still, one should be careful about agreeing to meet people they have met online.