Oh ya, you can get AWESOME stencils online. You can get thin plastic ones that you can re-use, or disposable ones that come with an already adhesive back. Then you just peel it off and throw it away when you are done.
There are several good companies out there, just search "custom stencils".
You can use regular paint if you want, I have mixed premium house paint with glaze and used that. For many different colors though you might want to get the smaller tubes of acryllic and mix them with glaze or a bit of water.
In a high traffic area or somewhere it is going to get touched, cover it with 2 coats of urethane.
To put stencils up that don't already have an adhesive back, use some spray adhesive (get it at a craft store). Otherwise bleed-through is more likely.