This is the image that will become your new poster. Though it can be any size, for the best results, I recommend a size of at least 720 pixels wide. Though your image does not need to be simple, I advise against highly intricate pictures, since the rasterizing process loses fine-details.
The Windows program that takes your digital image and processes it into a rasterized Adobe PDF for printing.
White Poster Board
($2 per three 22"x28" boards at Michael's craft store)
In this guide, I needed five poster boards for my 6 1/2' poster, so $4.
You likely already have these, or know someone who does. It only needs to hold a 10MB-100MB PDF file.
It's glue in a spray-can. You may need to be 18 or older to purchase it.
I used Kinko's Office Print and Copy, which charges $0.53 per color page. Black and white is $0.12 per page. For the poster in this instructable, at 32 sheets, the cost was $17. Your printing service will print out the PDF from your thumbdrive or CD. Note that Kinko's is meant for office copies, and doesn't have very accurate color. Local print shops can produce higher quality images, though price varies.
Clear 3M Packaging Tape
Purchase the thicker tape if possible, it's easier to apply without bubbles or folds.
Paper Cutter and/or Scissors
The paper will not be printed directly to the edge (called full-bleed printing), and has a thin border about 1/8" from the edge of the paper. We will need to cut along this border for every page, so a paper-cutter is extremely helpful. Scissors can be used in isolation (though it takes much longer), and help clean up bad paper-cutter cuts. I borrowed one from a friend who is a high-school teacher.
For hanging the poster to the wall.
1/2" Grommet Kit
Used for making stamped holes in the poster, to better nail it to a wall.