For some great tips about where to get your 1040 tax form and instructions, check out this link from File My Taxes Online, which is a useful resource with tax information and links. Their article about IRS 1040 forms starts out with some pointers about how to make sure you choose the 1040 form that's right for you.
But where can you find the actual forms? You can download them online, and some local government offices do indeed still carry paper forms and instructions, but be sure to contact your local library, post office, etc to make sure they have the forms you need. Did you know that you can also contact the IRS and ask them to mail you a 1040 form and instructions? I think this is a great option for people who don't want to download and print the info they need.
File My Taxes Online has other good info about what documents you need to collect to file your taxes. They offer some helpful checklists, which I think are good to look at now so that you have plenty of time to order any necessary paperwork that might be missing from your files long before your taxes are due. This article is a great starting point: http://filemytaxesonline.org/where-to-find-irs-form-1040-and-instructions/.