I’m sure the government would have a lot to say about that if you were to be totally honest with them 
Unless you have comprehensive profit/loss – cash flow data and receipts for deposits and expenses it could be a long process! I would advise you and everyone to KEEP GOOD BOOKS – it is ESSENTIAL to your business and to completing the tax process.
I actually do my taxes myself and always have – its a long drawn out process, but with good books its rather simple. I use quicken to keep my books and it automates quite a bit. My biggest problem is determining which field I am going to register as my profession – I usually look for a design or a marketing field – Im sure something more precise could be chosen but heck Ive havent had a problem as of yet.
For most of us we are self employed and a good number of us do this and nothing else so completing tax returns is actually rather simple. Those who have employees and have to have EIN numbers and pay workmans comp, insurance, withholdings, etc etc it is a much more tedious task. SE tax is fairly basic it was 15.3% last year – and as far as I know at this time its the same.
Course the IRS would much rather you pay as you go – they want that money in their accounts growing interest as quickly as possible LOL.
There was a tax specialist / or accountant posting here on CAP not that long ago – I think he may have attended one of the Miami Spring Break events not for sure though.
Best of luck to you.