Howdy hayesb2, welcome to the board!
We had a pretty good discussion on ribs a while back: Here's the LINK
The best way to cook ribs is low-n-slow. I cook them in a smoker at 225*. In a grill you would do this indirectly. To cook indirectly on a gass grill; if you place the food in the middle you turn on the outside burners, and it you place the food at one end you turn on the burner(s) on the opposite end. Since the object is to cook the ribs slowly you use a med to med-low fire, depending on your grill. Maintaining a constant temperature on a gass grill is pretty easy. I don't have a gas grill, but I do have a gas smoker. Once everything warms up and you have the knob(s) in the right position it'll maintain the temp.
Rib racks are not necessary. They are used to optimze surface are by standing the ribs up on end which allows you to cook more ribs in the same amount of grate space. Some folks don't use rib racks because they say their mop sauce runs off too quickly. You can skewer several racks of ribs with wooded skewers and stand the up in rows or roll the in a circle in place of a rack.
Removed the membrane from the back side of the ribs prior to marinading, rubbing or cooking. It will allow flavors and heat to penitrate the meat better. The ribs will also seperate easier when cooked and be easier to eat. It's my preference anyway.
Hope this helps! Have fun!