New fabric has a nice crisp look and feel and it can be tempting to jump right into a project once you get your fabric home, but taking the time to wash your fabric is an important prep step in sewing.
When you bring home your fabric it is full of sizing and who-knows-what kinds of chemicals. It might look nice but all that extra stuff just attracts dirt and can irritate people who are sensitive to chemicals.
All cottons and cotton blends can be washed in warm or cool water and then dried.
My favorite tip for laundering fabric is to wash it and then dry it until just slightly damp. Then while the fabric is still damp press it well. Drying fabric until it is totally dry can often lead to wrinkles that are permanently set, but if you take the fabric out when still damp you won't end up with those terrible wrinkles that just won't come out later!
If you don't have convenient access to a washing machine and dryer and really want to use your new fabric you can hand wash your fabric and then hang it to dry overnight. Try to remember to iron it while still damp if possible.