on disability and trying to get a business going (self employed)

Can anybody decipher what exactly I need to do and at what point I need to start reporting to SS and how it would affect my payments since I want to return back to work this March? Has anybody who is self employed returned to work on the trial work period while on disability?

My career was working on sportfishing boats and I started a part time boat detailing business in 2012 which got off to a really slow start as the charter boat I was on was too busy for me to do anything else. I was just getting going last spring when I had my heart attack and then dialysis started in which I had to quit my charter boat job and stop my detailing business. So I applied for SSDI in which I received my first payment in November.

Now, I want to try to go back to work when the weather breaks. I am starting to advertise my business but don't see anything starting up until March. I think it will be a good way to ease back into working as it will be flexible.

What exactly would I report as far as income since I'll be self employed as I'll have expenses such as supplies and insurance premiums which get deducted from my income? Or do I report gross income to SS? When do I let them know? Now? Or do I only report if I've made more then $750 in a month? Would my quarterly insurance premiums just be divided by the 4 month's for an average monthly expense or just subtract the whole premium on the month it is paid?

Thanks