This is from my book, I'm lazy...
Always check for the possibilities of dye bleeding and shrinking by moistening a small spot of your garment’s fabric in an inconspicuous place, using the soap or detergent and water of the temperature in which you plan to wash. Let the liquid sit a moment, then blot the spot with a white towel. Embroidery and other embellishments should be checked too. If cold water doesn’t budge the dye, don’t assume that warm water won’t—always test with what you will be using for your wash water. If you see any color on your white towel, I would recommend dry cleaning. Allowing the test spot to dry you will see puckering if the fabric is inclined to shrink.
Another point to make is that you should remove shoulder pads and reattach after washing. If there are covered metal buttons, don't soak the item long, or remove them prior.