There's nothing better than sitting around a fire in your own backyard, but store-bought fire pits can get pretty expensive, and unfortunately (but understandably), most states have pretty strict regulations on outdoor fires.
After clearing out the grass and leveling the base, which is just a galvanized fire pit ring, BobSacramanto poured a ring of concrete around the outside for the rocks.
Once the rocks were in place and the concrete set, he added a ring of paving stones to top it off.
The process itself isn't that difficult, there's just a lot of waiting involved because of the concrete.
Also, as the original poster and several others mentioned, it's a good idea to keep your distance the first few times you use it because the fumes from the galvanized coating can be harmful if inhaled. Other suggestions from the comments include drilling holes for airflow and adding a layer of gravel and sand to help soak up water when it rains.