re: Poker & Buying in for a short stack?
I was where you were only two months ago.
Don't do it. Yesterday I watched as a shortstacker buy in for exactly 20 bb. He called and folded most of his blinds away, then the third hand, called, flopped trip 10s, turned quads, and tripled up, winning a 23c pot... loled so hard when I saw it.
I recommend out the freerolls just a little bit more, at least to the $15-$20 range. Then you have enough for ~15 $1.00 buy-ins. 50 bbs is enough that you can afford to call with small pocket pairs and setmine. You can get it in with TPTK profitably, whereas you might be less eager with a full stack.
Patient, smart play is enough to run it up to $30-$40, now you can start buying in $1.50 or for the full hundred bbs.