I don't think you can use the stamps w/ this type of paint, b/c you won't have control where the paint goes.
I have used paint to spray items - normally I do tie-dye types of things. But you can spray almost anything. I do T-shirts, Dresses, socks, etc.
cotton material works the best. You can use cotton blends too, but the more cotton in the material the better. Wash and dry the fabric but make sure you DON"T use fabric softener.
If you're going to make a pattern/picture per se, then I would use a stencil of sorts. Make sure you cover up ALL of the shirt that you don't want that color to get on, then when you're done, move the stencil to another part, or use another color, etc.
have fun! i love doing this but like I said I usually do tie dye projects. But I love tie dye so this works for me.