Just a bit of advice on the lights.rad
When you are making a new map, open an empty .rad file called "mymap.rad" and yeah, you would put the maps actual name in and not mymap!
When you put a textured light in your map, and you want to change it's settings, copy the texture name from the original lights.rad and paste it into the new .rad
Your new .rad file should only have the names of textures you have changed.
Add -lights mymap to the hlrad compile line, and compile away....
Why,
It is easier to send a modified lights.rad to someone else, than ask them to overwrite their Original .rad file.
It won't generate redundant errors during compile, just overwritten warnings.
You won't have to e-mail your brother for a copy of the original valve.rad because you screwed that up also:-)