How do I know I am actually mining to my account?

Your hps will be in the thousands. If hps = 1 you're syncing. If hps =1 or very low you're in the queue.

I don't see anything in my wallet though

You're mining STEEM POWER, so it will go into your SP balance. To see if you found a POW, go to https://steemd.com/@youraccount and search for "found a pow".

Is it ok to mine on 4 different rigs with the same account?

You should use different accounts for each rig.