Until you find a better place to put your money, open an ING direct account and just sock that 300 a month away in there. It will start growing and you don't have to do anything but save your money. (PM me if you want a $25 referral bonus).
http://ingdirect.com
ING Direct is super legit. I found out about it here and have the majority of my money in it right now.
Good luck
