Basically to properly light a map you need a few things (which you only have "some" of them as you listed in your post).
These include:
1. A
Caulk Box - this is a hollowed out box that surrounds your entire map. The box must have the caulk texture applied to it, and then set only the inner faces to a sky texture (can be any sky texture as the skybox will replace it). This will not only help with lighting the map but also improve FPS for the map as it prevents the player from having to render the "endless void."
2. A
Lightgrid - this is a brush (not hollowed like the caulk box) that encompasses only the sections of the map the player has access to (the playable area). This will help with dynamic shadows such as the lighting and shadows displayed on the player's viewarms and weapons.
3. Reflection Probes - these serve 2 purposes (maybe more) and should be placed in every room/area of a map. They basically will add in any reflections of the map by displaying an "image" of the area it is placed in. This "image" is visible in the reflections of specular maps on models and brushes in the map, as well as specular maps on the player's weapons (ie a sniper scope lens). They also fix the "rainbow" lighting bug that many new mappers have (aka no reflection probes...).
4. World Spawn Settings - these are the settings that you input into the entity window (open it by pressing the 'N' key with nothing selected) which will allow the user to set values for the sun's direction, brightness, skybox model, reflection settings, and many more. These are essential for having a properly light map and it is recommended that you work off of Treyarch's preset worldspawn settings:
http://wiki.modsrepository.com/index.php?title=Call_of_Duty_5:_Worldspawn_Settings5. Lights - these are used in situations when the world spawn settings don't light an area the way you like (such as an interior of a building). They are also used for ambient lighting such as lamp posts and mood lighting. These also have scriptable properties when setup correctly and using a script.
Number's 1-4 are essential to properly lighting your map. I hope this helps!
JBird632