Thanks! i did try some googling before posting, but i couldnt find any good answers.. But i'l check out the links and stuff and see if it works!You should definitely learn the steps behind what Grim Wepa automates before you start using it. The program is meant for people that know how to use the aircrack-ng suite via command-line so that they don't have to type the commands each time.
First and foremost, you need to learn your way around linux. I suggest reading online how to maneuver and manipulate files/directories via the linux command line, and also how the application/argument structure works. A guide that can tell you nearly everything you need to know to get around in Linux is here: Linux.ie :: The Beginners Linux Guide
Once you get a feel for typing commands into the console, you can be ready to move on.
Second, you need to know if your wireless card is compatible. To know that, you need to know the brand, model, and chipset of your wifi card. If it's a USB wireless dongle, you can type 'lsusb' at the console to see what Backtrack sees your card as. Compare your wireless card and chipset to the compatibility list of wireless chipsets can be found here: compatibility_drivers [Aircrack-ng] Sometimes you need to install patched drivers in order for the wireless cards to work in Backtrack, and sometimes you need to buy a new wifi card.
Third, you need to understand how everything works. I suggest using a tutorial or guide to help walk you through the process; a decent tutorial for cracking WEP for beginners can be found here: Cracking WEP Using Backtrack: A Beginner's Guide - Ryan Underdown
Other than that, everything you want to do can be found using Google. If you want to know more about something, or if you have a question, GOOGLE IT! If you want to crack WPA, type "Backtrack crack wpa" and sift through the results. You should only post a question on these forums AFTER you've gone through every possible Google result and still have no answer (protip: posts should be few and far between).