I'm just wondering if anyone can tell me the ideal light level I should use for interiors? I don't want to use the standard light levels in vanilla, as I want to have it slightly darker to emphasize the details. I personally cant get the light just right when I'm experimenting, I'm either too light or too dark, and I'm just looking for some opinions. Thanks ^_^

It all depends on what type of interior it is.
Look at the light levels that Bethesda used for a similar interior to your own. They usually did a good job at creating the right atmosphere.

In my opinion, the types of candles/lanterns you place in the room are more important than the cell's light level.
Set the light level darker than you initially want, than light the room with candles/lanterns, this way you can control what areas you want dim/bright.

Don't forget you can use the dark_# lights for nice shadowy effects.

The biggest difficulties with lighting in Morrowind is the lack of consistency in original lighting across interiors and many users modifying the lighting wholesale by changing Morrowind.ini settings to suit their individual taste. Add to that lighting mods that change individual interiors and the base lights themselves.

Chances are, whatever you come up with will look different on another users screen than you intended.

Personally, I think most interiors are too light given that so many light sources are artificial. I would agree with Pluto to go dark with ambient and then add candles and lanterns.

Also, with caverns and the like, too dark to properly see (critical area's excepted) is good. It encourages nighteye spells and torches.

It's worthwhile taking the time to get it right given that lighting is so crucial to atmosphere.

I have done this. If I add anymore it'll just look bad, and I'm having trouble putting the lighting right. I have my caverns and generally dark areas done, I'm having trouble with standard houses, temples and shops.

EDIT: Ah, I found myself a perfect light level ^_^