This is a very simple project. I made a"rug slipcover" for a clearance Christmas Rug I found at Kohl's.
I purchased this rug for $1.19 this week on super clearance.
You can get any type of rug you want because you are going to cover it anyway.
I wanted to be able to wash mine since it was white. Essentially, all you are doing is sewing a pillowcase for your rug. Fold your fabric right sides together and Measure your rug. Cut the fabric an inch longer on each so that you can have a 1/2 inch seam allowance when you sew it together. This also helps in case it shrinks again in the wash. (I always pre-wash all my fabrics)
Your finished rug will look like this: