Texturing :Need help to show material through texture

Ok so i might be a guru on here but i’m still rubbish and i still need help lol.

Im working on my knife. But i want to place a logo on the blade by uv mapping it i know you need to use alpha maps (i think) to show the original material through the texutre, i’m just not sure on how to do this. In simple terms i am asking how you can get the original material to show up through a texture if you just want to texture a tiny little bit of a model. e.g put a logo on a blade but still have the blade material showing.

Any help will be greatly appreciated

Thanks

Reaper

This tut will help you http://mediawiki.blender.org/index.php/Tutorials/Textures/Use_Alpha_for_Object_Transparency

Thanks will take a look

Reaper