can anyone help me wiith this?. i am new to making sigs and i have many questions.. i use gimp and does anyone know were i can find a GIMP tutorial on how to add c4d's on the backround without covering up and affecting the render?

also i have a few noob questions..

i see in alot of tutorials "erase over your focal" what is a focal?

thanks guys

Both of those are general questions which would apply to both Gimp and Photoshop.

Firstly to make a C4D appear behind your render just move its image layer below that of the renders.
Secondly, a focal is the focus of your image; what grabs the attention of the viewer when they first look at the image.

I was recommended to look over this tutorial Signature Design Basics V2 it covers all you need to know about making signatures including terminology and techniques.