I figured out how to make this pretty brief. a real quick listing.
Suffice to say I know there's probably a few who have seen MD but not Twin Peaks, so this is for those who have seen Twin Peaks.
In Twin Peaks it is commonly understood that there are character groupings.
http://twinpeaks.wikia.com/wiki/List_of_characters_in_Twin_Peaks
One grouping stands out:
1) Black Lodge Inhabitants:
The Man from Another Place Enigmatic dwarf, inhabitant of the Red Room. Michael J. Anderson
MIKE Spirit, former associate and now opponent of BOB, inhabits shoe salesman Phillip Gerard, "The One-Armed Man" Al Strobel
Killer BOB Malevolent spirit, haunts the woods and inhabits humans, killer of Laura. Frank Silva
The Giant A supernatural giant who appears at key moments and provides Cooper with cryptic clues. Carel Struycken
Mrs. Tremond/Chalfont Link to the Lodges and intentions unclear Frances Bay
Pierre Tremond/Chalfont
Mrs Tremond/Chalfont's grandson, link to the Lodges and intentions unclear Austin Jack Lynch/ Jonathan J. Leppell
This list neglects to include Laura's angel.
The rest of the characters in Twin Peaks are, well, characters even if some of them have some pretty cool powers like talking to a log or something.
So real quickly, what are the Lodge Inhabitants of Mulholland Drive (lodge association in parenthesis)?
1) Mr. Roque (beyond good and evil)
2) Back of Head Guy (white) and Hairy Armed Guy (black).
3) Luigi (white) and Vincenzo (black).
4) Joe (white) and Ed (black).
5) The Cowboy (beyond good and evil).
6) Coco (black) and Louise (white).
7) Aunt Ruth. (beyond good and evil)
8) Wally (white) and Bob (beyond), and Rita Taggert. (black)
9) Irene and her bald friend. (beyond good and evil)
10) Emcee/Cookie (white) and Magician. (black)
11) Blonde Camilla (Camilla's angel, white)
Characters who are not Black Lodge Inhabitants...
1) Diane/Betty/Laney/Dan/Bum
2) Camilla/Rita/Carol/DeRosa/Herb
3) Adam
4) Lorraine
these lists might help to clarify some of the character relationships. this should really explain the entire movie for those who understand how The Black Lodge Inhabitants function in Twin Peaks.

