restarting

Im trying to write a simple program using pico, I remember how to write in C Syntax ect but for the life of me cant remember how to compile. i have tryed gcc -o filename.c filename . i remember theres some thing else tho.. its been about 10 years sense i have done anything. any help?? www with code. i can still get around in the terminal box good just cant remember how to compile and run. Im usin powermac g5 i bought about 6 months ago..

thanks
matt