There are a couple of things that you'll need to consider. First, make sure you get insurance to cover you and the equipment. The kind of policy, costs, etc. will be totally dependent upon your state laws and availability of insurers. In Maryland, the only way I could get coverage to take my tractor off my property and be covered was to get a landscapers policy. It will cover my tractor and all of the equipment listed on the policy for $500 a year. Key words are equipment listed on the policy. If it isn't listed, don't remove it from your property.
Now what to charge..... hmmm - very subjective. Our family (me or my daugher) do a couple of lawns in our neighborhood. I've set the price at $35 per yard. It takes a little more than a hour to do so I thought that it was a fair price. I will adjust the price depending upon the size and/or terrain of the yard. I haven't done any brush clearing. If and when, I do that I'll charge it out at $35-45 per hour. If at all possible, I will try to use a fixed price amount as mentioned earlier. If the work gets done quicker, more money in my pocket. If it takes a little longer than expected, note the problems and adjust later. Fixed pricing works well and people do not think that you're screwing them if the job takes longer than you anticipated. The only way I would charge by the hour is if I cannot come up with a reasonable guess as to the length of the job.
Hope this helps.
Terry