I had a tax service do mine once and I thought, hmmm I can do that and I did for the last 40 years.

I use the 1040A and its very simple.  Your tax booklet goes "step by step".  Like stated above, your employer must give you a W- 2 form (you have three of them ( state, federal, and your copy)  which is the base.  Your bank, credit union must give you a tax statement of all the interest you got.  If you have stocks etc, they too must give you a tax statement and tell you where all the figures go on your 1040A.  

What is new this year.  IF you own a home and pay property taxes (city, county, and state), you can deduct a portion of it EVEN if you don't itemize and take ye olde standard deduction.  Simply follow the instruction on how to do it - there is a form on page 33 that you fill out (in pencil, you are going to make mistakes).  

You MUST keep a copy of the forms you send in plus your 1099 etc. given you by your bank, credit union, mutual funds, stocks etc.  READ what is required to send to the IRS.  Not every thing goes, but you must keep everything.
 

Read Common mistakes made by taxpayers in your IRS tax booklet.

-and remember, if your state collects taxes, you MUST check and see if you are required to file (most states do).  If you are not sure, call your state's Revenue Service and they will tell you or go any public library to pick up a state booklet, their instructions are very similiar to the federal (a few exceptions, so you must read it line by line too).

Again, both have simple step-by-step instructions, and DO the draft in pencil, go over it several times checking math errors, putting the numbers in the wrong lines, transposing numbers.

Buy a cheap calculator.  Next day recheck your figures again, line by line.

Above all,  have fun doing your taxes like the rest of us and DON'T wait until April 15th to do them-start as soon as you get all your statements.  Jan