You file it as a schedule c for a small business. I use to babysit, I claimed every dime I made! If the parents wanted a receipt that was fine with me because I did claim it all. Filing as a business you can take alot more deductions. I used pretty much my whole house, my car, etc for the business so a portion was deducted. My husband also runs his own business and has for 10 yrs. I still have a small business online, so I file for my business and dh's. I do have a full time job now too.
I use turbo tax and have not had to be audited at all. Actually once for the state I did. We were getting medicaid at the time and the did a sting operation on all self employed people. I brought in all my documents, bank statements etc. We passed their aduit some 3 hours worth of searching.
File as self employed and claim all that they paid you. That's all that you need to do. Since you didn't pay throughout the year you'll owe money and probably a penalty since your supposed to pay quarterly when self employed.