You will need at least an hour to make reasonably good rice for sushi.  The first half hour the rice will cook and the second half hour the rice will need to cool with a sushi rice solution.  This way when you put the rice with the fish it does not partially cook the fish.

Rice the rice with your hands and running tap water.  Get as much cloudiness out of the rice as you can and be sure there is nothing else in the rice besides rice.  Sometimes small stones can appear and make for an expensive trip to the dentist.

Put your stove top on medium heat.  Place the rice and the same amount of water plus a few tablespoons in the pan and cover with a tight lid so steam does not escape.

Bring the rice and water to a boil.  Gregory Hillman suggests this because it may kill some bad things in the water.  Reduce the temp to low and let the rice simmer for 15 minutes.  Then take the rice off the burner and let it sit hot for 15 minutes.  When complete add the rice solution.

Add a solution of salt, sugar, and rice vinegar to the rice.  I like extra sugar until it will not dissolve anymore but it is up to you.  Just be sure to coat the rice evenly with the solution and cool the rice in the fridge.  I use about a half a cup of solution for 2 cups of dry rice.

Cool the rice in a fridge covered.  You can also just let it sit covered.  I use a piece of cloth or just a lid.

That is it.  If you follow these instructions I have found that the rice turns out excellent every time and it is very simple.  Just be sure not to over or under cook.  I use the timer on the microwave to ensure that each 15 minute segment is followed correctly.