Videographer...what to charge ?

So I've done alot of filming the last couple of months and now I have guys that want private shoots done. I will do them here at my place because I have met these persons before and they have been screened. So, my question is, how much to charge for this type of work. Since it's not going on my site, I really don't want to lowball myself because time is money and I need a new g5 powerbook.

And legally, what are the requirements for this kind of work ?

I'm kind of curious as to what someone would charge as well. I work camera at some of the sporting/concert events where i live and get paid a flat rate of between 200-300 per event which is about 5-6 hours of work.