If you aren't feeling comfortable you should hire a tax person. Depending upon the size of your business, it may become more difficult/ Do you have employees? If not, it may be more straight forward then you think.

You need to file a SE form. Hopefully you've kept track of all the expenses throughout the year because you can deduct them. Things like utilities, rent, supplies to run daily operations, gas mileage, medical insurance, etc. My suggestion is to use each and every single thing you can come up with to use as a deduction. That will be deducted from your overall gross earnings and leave you paying less in taxes, might even result in getting some money back possibly!

Go to the IRS website to find answers too. They're pretty good about offering directions for every form.