Do you need to file original returns or amend ones you did file?

You can't do a prior year return online or efile it, but you can buy either the cd or download the desktop versions for the last 3 years from Turbo Tax here....

http://turbotax.intuit.com/personal-taxes/past-years-products.jsp

Or you can check for  Turbo Tax for all years on Ebay or Amazon, etc.

Either way you will have to mail in your return.  And if you are doing more than 1 year, send each year in a separate envelope. Sometimes the IRS will just staple all the sheets together and miss a second return.

You can fill out the blank forms for free.

Here are some blank forms & instructions for 2016

1040 https://www.irs.gov/pub/irs-prior/f1040--2016.pdf     

Instructions https://www.irs.gov/pub/irs-prior/i1040gi--2016.pdf

1040A https://www.irs.gov/pub/irs-prior/f1040a--2016.pdf    

Instructions https://www.irs.gov/pub/irs-prior/i1040a--2016.pdf

1040EZ https://www.irs.gov/pub/irs-prior/f1040ez--2016.pdf    

Instructions https://www.irs.gov/pub/irs-prior/i1040ez--2016.pdf

2016 Tax Tables https://www.irs.gov/pub/irs-prior/i1040tt--2016.pdf

Publication 17 Tax Guide for 2016 https://www.irs.gov/pub/irs-prior/p17--2016.pdf

Don’t forget your state.  And you will have to print and mail your returns.  So be sure to attach copies of your W2s and any 1099s that have withholding on them.  You have to mail federal and state in separate envelopes because they go to different places.  Get a tracking number from the post office when you mail them for proof of filing.

FOR 2015

Here are some blank forms & instructions for 2015

1040 https://www.irs.gov/pub/irs-prior/f1040--2015.pdf     

Instructions https://www.irs.gov/pub/irs-prior/i1040gi--2015.pdf

1040A https://www.irs.gov/pub/irs-prior/f1040a--2015.pdf    

Instructions https://www.irs.gov/pub/irs-prior/i1040a--2015.pdf

1040EZ https://www.irs.gov/pub/irs-prior/f1040ez--2015.pdf    

Instructions https://www.irs.gov/pub/irs-prior/i1040ez--2015.pdf

2015 Tax Tables https://www.irs.gov/pub/irs-prior/i1040tt--2015.pdf

Publication 17 Tax Guide for 2015 https://www.irs.gov/pub/irs-prior/p17--2015.pdf

I am concerned that you said you need to file returns for a couple of past years and then you said you want to amend those years.  Which is it?  Amending is a special process you only use for a return that has already been filed, accepted and fully processed.  If you have not filed tax returns for those earlier years--ever-- then do no click on anything that says "amend."  Amending would be completely inappropriate for returns that you did not ever file.

You already have excellent information from VolvoGirl about how to file returns for a prior year.  If you actually filed those returns incorrectly at some earlier time, post back for help with how to amend and correct mistakes or omissions.

And you asked about how to get your W-2's--did you not save them when you got them from the employers?

W-2's come from your employer, and they have until Jan. 31 to issue it.   You might need to phone, drop in, email and/or snail mail an old employer to make sure they know where to send your W-2.

https://ttlc.intuit.com/questions/2561916-how-can-i-get-a-copy-of-my-w-2

Other ways to get W-2’s:

Pay Social Security $86 per W-2:

https://www.irs.gov/help-resources/tools-faqs/faqs-for-individuals/frequently-asked-tax-questions-an...

You can get a wage and income transcript from the IRS:  It will not show the actual W-2, 1099’s, etc, but will show the income information the IRS received.  It will not, however, show your state information. It will only show the federal information.

https://www.irs.gov/individuals/get-transcript