I would take it on off days also. I do not know if you are thinking Monohydrate or CEE, but still, off days it should be taken also. Mono by many standards requires a loading phase, some agree, some don't. I am in the loading phase camp myself. Tried and true.
I am also a fan of pre workout, as I am a firm believer that increase blood flow will help uptake of creatine to the muscles. If you can afford it(mono I am talkking here), take it both pre and post.
If doing CEE, divided doses of 3 gr. during the day should work fine. Say 3 gr. prior, and then 6 hrs. or so later 3 more gr. Most containers will specify somewhat their recommendations.