Some excellent advice already. Something that I found edifying was the customer/iteration/planning advice here: Extreme Perl. I think their advice, especially for project management issues, is excellent. Story cards and feedback advice in particular.
As far as pricing. It really depends. Some contractors charge $150/hr and are largely worth it. Others charge $25/hr but take 10 times longer so aren't worth it at all. I charge $30-$80/hr depending on the type of work. I tend to screw myself because I don't enforce the original spec well enough so end up adding hours for free. An entire project might look like so many hours that you're willing to do a project rate too. Whatever hours you come up with for your original estimate, double them. "Under promise, over deliver" will make your customers happy. The converse will make positive references scarce.
Being a good contractor takes hacking skills but it's only a slice of the problem pie.