I don't keep my components in a 'closet'. I keep them all on a 14"x16"x36" tall 3 shelf unit. It is open front, back & sides. Makes it easy access and plenty of air circulation. Currently it's in the family room, but will be moved into the office room when the new flooring in the house in finished.
To keep the setup easy for me to remember, I created a visual cheatsheet. I have attached pictures of the cheatsheet and the components.
