I like just plain long-grain white rice for most things, don't wash it beforehand (unless it is really grotty and has been on the floor or something!) as it will take starch out of it, I use a cup or mug to measure. If I use 1 cup of rice I pour 1 1/2 cups of hot stock (or hot water for plain rice) into the pan on top of it, bring back to the boil stirring gently with a fork to keep the grains seperate and stop them settling and sticking on the bottom of the pan. Then once it is just starting to bubble turn it down to below the 'low' hob setting, as low as the heat will go without it being off, put a tight fitting lid on, and leave it for 10 minutes or so - this should be when you can see dimples and holes in the top layer of the rice, check it is just cooked to the right texture (it should be if your water to rice ratio was correct!) at that point take it off the heat and leave, covered with the lid still, for a couple of minutes to absorb any remaining moisture. Then separate the grains by stirring through with a fork and serve.
EDIT: One of my favourites is tomato rice - the exact same as above but I also chuck 3 finely chopped tomatoes and some herbs into the pan and carry on exactly the same cooking instructions - works a treat!