Are you doing baby backs or spares?
Both are pretty easy to prep..
If they are spares then you'll need to remove the thick flap on the meaty side of the ribs. Pull up on the flap as you cut it off and set it aside:
I also recommend removing the membrane which is a plastic-like film over the boney side of the ribs that keeps the smoke from getting through and it's not very pleasant to eat.
Slip a knife, spoon, screwdriver or other sharp object under the membrane to get it started then use a paper towel for better grip and pull it clean off. It may take a few tries if you've never done it before. (Catfish pliers will also work in helping you to grip the membrane and pull it off)
Once the membrane is removed, apply about 2-3 TBS of rib rub to the meat on the bone side of the ribs then flip the ribs over and apply another 3-4 TBS to the meaty side. Apply more if you need it depending on what kind of rub you use.
If you use a rub with lots of salt, (store-bought rubs/seasonings) you'll probably want to use less. If you use a good homemade rub recipe, make sure it is one with only enough salt to bring out the flavors and apply a little more. A good rule of thumb is to apply enough rub so that you just barely see the meat through the rub.
You will also want to apply some rub to the flap piece that you cut off of the spare ribs.
Note: to help the rub to stick better, apply a thin coat of regular yellow mustard to the ribs just before adding the rub. The mustard will create a nice crust, holds the rub onto the meat and does not taste like mustard after it is done cooking.
Here is what my spare's generally look like when they are ready to go on the smoker:
Lay the rubbed ribs aside and go get your smoker setup for smoking at 225-240 degrees F.
Smoke/cook the ribs until they are tender. For baby backs you are looking at 5-6 hours, for spares this will be closer to 6-7 hours. Check for tenderness by pulling (2) adjacent bones in opposite directions. If the meat tears easily, the ribs are tender and ready to eat.
Oh yeah.. the flap of meat should be smoke/cooked as well and will be ready to eat in about 1.5 to 2 hours and is what I call the chef's treat.
Enjoy the ribs, let us know if you need more help with any of this.
Here's some pictures of the finished product
Cut in half for the Bradley smoker..
Smoking spare ribs and baby backs on the Weber Smoky Mountain