how to set general setting

This is in General Settings, how do I set the parameter. For example: in Miscellaneous, what should be set in check: IP check or no checking? how many hours should be set for time lock out? I was testing the poll, if I set IP check and 200 hours locking time out, my co-worker voted in different computer, then I was not able to vote, I only see the result. I don't know if we share the same IP address. We do use the same router. If I set no checking, and locking time out 2 hours, we both can vote, but I am afraid that we can vote more than once. Can anyone help me explain how to set these parameters?
Another question is about Edit this Poll, what really mean disable (diable poll question)? Does that disable mean you cannot vote, but you can still view the poll or poll results?
Thanks you
Lynda