This is not a tutorial about textured lights, but rather a tutorial about the placement of the lights.rad file for the source SDK. For an actual tutorial about textured lights you can go to the following url for a tutorial written by Blink a while back, http://www.cs-maps.org/index.php?page=t ... lights.htm
Textured lights for the source SDK are exactly the same as before (to the best of my knowledge). So create a new text file.
Now open up the text file and enter in the standard texture light information, that is the name of the texture, an RGB value for the color of the light, and the lights brightness.
Now go to file>save as and save the file as lights.rad
The lights.rad file goes into the "game directory". If you are unsure of what your game directory is, open up hammer and go to tools>options>game configurations> and the game directory is in the second to last box.
Here is a sample of textured lights in a map. The lights are set a little bright, but since there is no light entity in the room you can see that it is working properly.
I am not entirely sure if this is correct, all I know is that after a half hour of trial and error I found the proper folder for me which is C:\Valve\SteamApps\***@sfuhs.org\sourcesdk\cstrike_sample_content.
This folder also happens to be my game directory folder.