what's a good stake?

I figure 50 X small bet is a good stake to play with in limit hold em. I believe one can weather a few 2nd best hands and still have time to comeback. Losing more than that may indicate you are about to go off.

50 small bets is a reasonable stake to play for a single session of limit hold'em. If you hope to play for longer than that, you should shoot for more like 300 large bets as your bankroll.