This one is kind of long and the image is a bit big, but I couldn't think of any other way to get all the necessary info in here. Sorry if it's too much.

Maya's Attribute Spreadsheet is a quick way access attributes for many objects at once and may save you many trips to attribute editor if used properly.

This example will show how you can use this to adjust multiple lights all at once.

In the scene below, "1" shows a screen capture with numerous spot lights. Number "2" shows how that scene renders... obviously way too bright. To fix this, open the Attribute Spreadsheet (under window-->general editors-->attribute spreadsheet..). Hmm, nothing in the spreadsheet... that's because nothing is selected. So select "all by type-->lights" in order to populate the spreadsheet. You can, of course, shift select whichever lights you want to work with.

There are a couple dozen attributes you can change under various tabs. You may need to scroll some to see all the attributes you can play with, feel free to experiment. For the scene below, the intensity needed adjustment. Drag select the intensity value for all the lights, then in type the value you want, in this case 1. The result is show at "3"

In this scene the lights were softened up also. These being spotlights, the adjustment was made to the penumbra attributes, which were changed from 0 to 3. The result is shown in "4."

The Attribute Spreadsheet is a quick way to make changes to virtually any object in your scene (not just lights).