Seriously, a CD won't give you anything unless you're talking serious money or long times. Even if you get what's considered a good interest rate right now, like ING's no minimum balance CD for 1 year minimum at 2.6%. Don't expect to get much over that. Put in $1000, and you get a whopping $26 extra by year's end BEFORE taxes.
Don't get me wrong, investing is a great idea and the earlier you start the better, just don't expect something like that to pay for an H22 unless you have the cash up front and just want a few bucks extra.
As Rob said, your priority probably should be schooling not the H22...unless you've got the cash to pay for both (or aren't paying for school perhaps). Just don't forget that school will probably require an increased eating and partying budget....which may cut into your H22 budget.
b