here's what I can think of. The bugzilla isn't the best medium for tracking things, however, in the absence of any other tool (barring Shreyank's FSoC), here's what can be done:
- request the mentor create a BZ which contains the scope of the task, the studying to be done and, the estimated hours. - iterate the above for as many mentors who will be agreeable - list the BZs in a table for the interested students to work on - organize a telephone conference for the student-mentor pairs along with the administrator of this effort and set the ball rolling - take a fortnightly assessment over IRC in terms of work done (updates of work can be posted as comments to BZ)