I had a few questions from people who didn't know how to create their autoexec files, so I decided to write this tutorial for them, and anyone else in need.
Step One
Open notepad (Start > Program Files > Accessories > Notepad)
Step Two
Input the information you want in your autoexec file (these configurations will be set everytime you boot up Counter-Strike: Source, and anytime you run it in console via the
exec autoexec command).
Step 3
Time to save what you have. (File > Save As...).
Step 4
Browse to your cfg directory, and save the file as
autoexec.cfg. Refering to the picture below, ensure you have the name (autoexec.cfg) and the type (All files) selected correctly. Once you are done, hit "Save". (Your Counter-Strike: Source directory should be in the following location:
C:\Program Files\Steam\SteamApps\username\counter-strike source\cstrike\cfg. If it is somewhere else, you should know how to browse to it. If not, just ask).
And there you are. Enjoy, as another side to CS:S is now avaliable to you. Make your game more personal.
If you have any further questions, you're free to ask. At the moment I'm putting all the guides I've written in my sig, so refer there if you feel like putting on your code-monkey hat.