Step 1: Rice theory
After you cook it a few times you'll have your own ideas about how much water to use, for now, we'll walk the middle of the road and use 1 part rice to 1.75 parts water.
If you've added in too much water, fear not, simply cook your rice longer and crack the top allowing more moisture to escape. If you've added too little water, you're in luck, because you can always add more!
Ideally you won't need to make the adjustments described above when you're cooking rice, and your batches will come out perfectly fluffy, moist, with just the right amount of chewiness and only enough starchy glueyness to keep the grains clumped together enough to get them into your mouth.
White Rice vs. Brown Rice
Cooking methods vary slightly for white and brown rice. White rice is generally speaking, cooked for a shorter period of time (20-30 minutes), with less water. Brown rice is cooked for a longer period of time (30-40 minutes), with more water.
Rinsing the rice
Some methods suggest rinsing rice before combining it with water in the pot. This is an attempt to "wash off" the excess starches on the outside of the rice which purportedly make the rice gluey. I haven't noticed any real difference in final results between doing this and just going straight to the pot. The real quality comes from the cooking method in my opinion.
Toasting the rice
Other methods call for the rice to be cooked in the pot for a few minutes before the water is added in. This is a useful technique when trying to impart additional flavors to the rice. When making a middle eastern style basmati rice, or an Italian arborio rice used in rissoto, I would fully suggest this process, however, for just making plain, unflavored white or brown rice as we are in this Instructable, this step is unnecessary.
I just find it important to always state that when cooking, there's no need to follow the recipe exactly. If you can understand what's going on inside the pot, then there's often many ways to cook something delicious and successfully. Take the recipe as a grain of rice.