Yes, I file my taxes as self employed. I have done so off and on since 2008. You need to file your regular 1040 as well as a Schedule C, which is your self employment form. There may be other forms too, depending on your industry, etc. but those are the basics.
You do get some breaks for your expenses. You need to keep diligent records of what you spend. Such as, with my business, I do crafts and writing, so I keep track of what I spend at Hobby Lobby, but also expenses such as postage, paper, and ink. As long as it was something you genuinely use for your business. Save all your receipts!
For me, I find record keeping on paper with good old fashioned ledger paper easier than doing so on the computer, but some people rely on bookkeeping software. It's really up to you.