Coulor Troubles

Ive Made a gun model in Blender and i know how to like colour it blue and stuff but how to i put a texture on it?

cmon, put more effort than a silly thread like this, go into blender general (this doesnt seem like a game engine question) and go into the tutorials. pick a few, and read em. if that doesnt help, use the search function

also check the sticky topics in blender general