Quick Tip: Taking Screenshots in Counter-Strike: Source

To take a screenshot in Counter-Strike: Source all you have to do is press "F5" on the keyboard. The screenshot will be saved as a JPEG (.jpg) file, named "<map name><screenshot number>" (e.g. "de_dust0003") in the steam\steamapps\accountname\counter-strike source\cstrike\screenshots folder.

Happy fragging.