Since I'm new, I'm wondering how the difficulty rate factors into the whole mining scenario? I'm just starting up as a CPU miner and am just curious. Thanks

Well, difficulty is just that: it determines how difficult it is to find a solution for the block. The higher the difficulty, the hard it is, the more hashing power or more time it will take, to find s solution. The results (hash/sols) your miner produces has to be below (smaller value) the current difficult to solve the block. Given a set network hash rate, a higher difficulty means longer block times, so less blocks are mined over time. HTH.

I should also add that, for all PoW coins, difficulty adjustment is the mechanism the network uses to maintain the network block time target. For ZEC, that's 2.5 minutes per block. So, when the block time goes below 2.5 mins., the network will increase the difficulty to slow down the block finding rate, and decrease the difficulty when it goes above 2.5 minutes to speed things up.

Thank you for your replies .. not all that sure i understand ... my minors are all set with low difficulty .. like 64 or somewhere. why would I want ot change then to a higher rate .. and can you tell me a good number to have as a pool dificulty

If you have your difficulty set low, your miners are spending a lot of time submitting shares, which is inefficient. Submitting large numbers of easy shares isn't going to pay you any more than submitting fewer, higher-difficulty shares; the pool takes your difficulty into account for the shares you submit.

will this affect my Sol/s by increasing difficulty ... what would be a good number to start with?

That depends to a degree on your rig. Why not be adventuresome? Try experimenting and observe the results. You’ll understand more about mining that way. Start by doubling the difficulty you are using now, then watch for a day, then double it again, and so on, until you’re happy with it.