fair-share scheduling has to do with how a multi-tasking o/s handles each separate process. look up "process scheduling" - that should give you a lot ot links.
i think that fair-share has to do with allocating an equal amount of processor time to each running process. off the top of my head, i've heard of FIFO, round-robin, and ... hmm. that's all i remember. but there's lots more.
the whole scheduler problem has to do with optimizing the use of the processor. there's lots of problems with the comparitive speeds of RAM, the HD, the cache, ect. it's not a fluff-topic.
if you want to impress your prof - then there's a lot of development being done on the linux scheduler right now. it's been practically unchanged since 1991, and a kernel hacker named Ingo Molnar is busy optimizing and modularizing the scheduler in the new develpment kernels. you can check out the lkml or kerneltrap/traffic for more info.