I use the blue water eraseable pens and they always work great however don't try to use them after the quilt is sandwiched with the batting/backing. They will sometimes bleed through and not want to go away. But, if you mark your top ahead of time, they are great. Just spritz with water and they are gone.
As to washing...others have given good advice. I will say that if you don't like the "crinkle" look then lay the quilt flat to dry, don't put it in the dryer. I've had good success with this. Also, pre-wash and machine dry your fabrics.
Colour catchers catch any dye that comes from the quilt in the wash into the water and then it doesn't settle back on your quilt. It isn't to stop a quilt from bleeding, just to catch loose dye in the water. They are available at most big box and grocery stores.
Watson