Calculating the odds of hitting a hand on the flop

The only stat I know off the top of my head is that you will only flop a pair or better 35% of the time. I think what you should try to do more with those hands (5/6o) is play them in late position and as cheaply as possible (unless you think you can steal the blinds). From the what the board reads, you'll have a better idea of how to play it from there (i.e. if you are open ended after the flop you have about a 32% chance of making your straight, so if you are getting at least 3 to 1 on your money you should call to see the turn etc.). If you want actual odds charts and such, almost any poker book has one, or just google it.

Good Luck.