I have very long hair (to my butt) that has a tendency to tangle. When I wash my hair, I'm careful not to rub it roughly against my head. I tip my head back, face to the ceiling, and shampoo from the scalp, allowing the shampoo to work it's way down the length of my hair. I use a wide tooth comb to keep the hair organized as I wash it. Also, when I rinse the shampoo from my hair, I continue to keep my head tipped back. Basically, I keep my hair slicked back for the entire washing/rinsing process to minimize disorganization and tangling.
I never rub my hair with a towel; I squeeze the excess water out of my hair, and then wrap it in a towel. I second the motion on the Tangle Teezer hairbrush; awesome brush! I also use a brush called The Wet Brush. Both of these brushes are great for detangling my hair with ease, and they are both inexpensive. While my hair is wet though, I stick to a wide tooth comb.
I cover my hair at night. I usually make a loose braid at the nape of my neck, and then cover my hair with a satin sleep cap.
It sounds like a lot of work, but I ADORE my hair. It is all so worth it to me.