Render a layer separate from other

well, no responses for my question, i’ll make another, does anybody knows how to make a layer render completely separate from another? i mean, that a layer doesnt have anything to do with another, i’m guessing a solve for this problem http://blenderartists.org/forum/showthread.php?t=84100
so anybody knows how to do this, i tried enabling the “layer” button so the lamp only affects the meshes in the same layer, but it doesnt work with caustics!!! somebody knows a variant of it? o something that can help me out? thanks!

I am no expert but there are some great video tutorials on this web site. If you have the connection. Check out Intro to Render Layers in the compositing section.
Heres the link
http://www.geneome.net/index.php/blender-tutorials/

thanks ibkanat, im already doing some test with nodes… thanks a latte!