Nothing to it, but you need the right rice. "Regular" i.e., long grain, rice turns to mush. Italian short grain Arborio is the key, as is paying attention.
Basic process is as follows (all quanitities are approximate)
Saute about 3/4 cup finely chopped onions (I use shallots sometimes) in olive oil. Add 1 cup Aborio rice & saute for a few minutes until the rice is slightly translucent. Don't brown the onions or the rice.
Add warm chicken stock about 1/2 cup at a time & stir continually until each dose of stock is absorbed. Keep adding stock until you have the consistency you want and the rice is done. Should take about 15 - 20 minutes total and use 2 - 3 cups of stock, but taste frequently toward the end, season appropriately, etc. Main thing is to pay attention & keep stirring.
When done, stir in about 3/4 cup freshly grated Parmigiano-Reggiano. Eat immediately -- if it sits and cools down, it tend to congeal.
Variants: Use seafood stock & add shrimp, squid, etc. toward the end. No cheese.
Soak dried porcini mushrooms in the chicken stock (strain before adding to the rice), add to the risotto at the beginning.
Asparagus, peas & other spring veg. are also good. Cook asparagus first, use raw (or frozen) peas.