at a store possibly michall's craft store I know they have some twilight saga posters there!
By getting your mom to do it for you.
"A poster is any piece of printed paper designed to be attached to a wall or vertical surface. Typically posters include both textual and graphic elements, although a poster may be either wholly...
A poster is a printed marketing material commonly A3 and larger and to be defined as a poster they must be attached to a vertical surface.
children like bright large fonts with pictures and adults like info. and aren't bothered about the colours ect.