I think you lack a basic understanding of how this works.
You need either software to hold your hand, or a professional to do it for you.
You take your gross income, make all your deductions, THEN you figure your amount owed based on your net income.
You're not going to spend more than a hundred dollars on the software you need. Some options will cost you less than that. It's worth every penny.
All you worry about doing is plugging in your numbers when prompted for them by your tax software, and let it do the figuring. I've NEVER filed by hand, and wouldn't recommend it for you. Use software, or get an accountant.
This is the best response thus far to the OP. The OP shows a lack of basic understanding. Your tax bracket is determined by what your net income is after all deductions and credits. You do not write off any of the net. If you do not pay any taxes at the end of the year you are basically not making any money or are cheating on your taxes. Don't forget that you also have to pay FICA and Medicare taxes.