I only work with fabrics that can be washed in a machine. That being said, always check your tags. Mine will say "Normal Wash" or "Gentle Wash."
The most important thing I can say about washing clothing is NEVER wash in HOT water or dry on super high heat. Heat degrades the material faster than regular washing. It can cause shrinking and warping of the fabric. Also, the colors can bleed, and will definitely fade faster. (The only exception to this rule is if you have some sort of bug infestation.)
For Normal Wash - Use the COLD/COLD, COLD/WARM or WARM/WARM setting on your washing machine. Typically, newer machines have a "Normal" setting, feel free to use this. You can dry low or normal in a regular machine.
For Gentle Wash - Use the COLD/COLD setting. You can tumble dry low or hang dry. If you have an older dryer and know that it tends towards the Hot side, definitely hang dry.