a few odds questions

[Scooterdoo]

A few questions:

1) what are the odds of getting a pocket pair?
2) what are the odds of getting at least a pair when the flop comes if you are not dealt one?
3) what are the odds of getting at least a pair when all 5 board cards are delt if you are not dealt one?
4) combining all 3 above, what are the odds of any random hand being a pair or better after all the cards are dealt?

Last, can anyone recommend any good sites or resources that summarize most of the holdem poker odds one would come up against. I know quite a bit of it, but would love to find a comprehensive source that lists everything in one place if it exists.

Thanks