I think the only real problem you'll encounter with not having the correct lights.rad file would be your textures not emmiting light.
But on the subject of lights.rad, make sure your pathnames are correct. I found it easiest to go into texture replace mode, and copy + paste the texture into your rad file. After the name of the texture, hit TAB twice, then enter in your light values. R G B then brightness.
Example
LIGHT_5a ---[2 Tabs Here]--- 255 255 255 1000
This will have texture "LIGHT_5a" emit a white light with brightness = 1000
The values follow the same values as a point light, but texture lights will not be as bright, so boost the brightness number a bit.
Try moving the lights.rad file into the same directory as your maps, or the compilator. It saves a lot of time if you have all your mapping resources in one place.
Now to run the game:
In steam, just run the game, open up the console ( ~ ) and type in "map mapname" ..... without the quotes of course.
You might have to activate the developer button first. To do that, go to options, keyboard, advanced, enable developer console.
that should work perfectly considering you have your compiled map directory correct.
(steamapps - your account name - half life - valve - maps)