Cooked rice can be kept in the fridge for ages. Store it in a tupperware (or whatever). When you want to reheat it, crumble it into a bowl. Don't break the rice grains, just try to declump it. Add about a tablespoon of water and cover it with a wet paper towel. Heat for one minute, mix it up with a fork, heat for another minute, mix it up, and continue until it's steaming. Remoisten the paper towel and add more water to the rice, if necessary.
Generally, the reheated rice will cool quite fast so I don't recommend that you eat it plain. I mostly just use it when I'm making donburi, stir fry, or curry - the meal/sauce served on top keeps the rice warm and I've found that the reheated rice actually sops up liquid better.