How to use a power sewer snake.

I figure you're reading this because you want to know how to use a rooter. If you're afraid of things that typically go down the toilet or have a sensitive sense of smell, don't read anymore.
One of the things you might find yourself doing as a landlord (and maybe as a homeowner) is snaking out your sewer drain. It might be because of roots, papertowels, kid's toys, tennis balls, rags, feminine hygiene products--ok you get the picture. I've found all of the preceding items. Pity me.
Both Home Depot, Lowe's, and Harbor Freight Tools carry plumbing snakes. I bought the one by Ridgid for around $400. Harbor Freight's runs around $250-300, but doesn't look as sturdy or as safe, as it has an open cage design as opposed to the plastic shell that surrounds both the Ridgid at HD or the model that Lowe's carries. Also, buy the PVC gloves that are nearby.
In any case, it generally costs around $200+ for a drain cleaning service to come out and snake the main line. I've heard that Mike Diamond charges $99 for any drain, so that would be a good deal, depending on when his guys are available. Most inexpensive rooter services take at least 8 hours to get to your job, in my experience. So if you've ever had a rooter guy out 2-4 times, you could've bought the tool.
Now that I've blabbed your ears off (eyes off as you're probably reading this) I guess I should stick with the HOW TO in the title:
1. Take off the cap to the cleanout (you might want to be wearing those gloves, eye protection, and shoes you don't care about--I wore my Tevas today, but I knew I could just wash off my feet.)
2. Let water flow out while you go plug in your snake and determine where the best place to put the machine is--that's why you take off the cap BEFORE you bring your snake over.
3. If you haven't put on the PVC gloves yet, now's the time.
4. Place the snake 2-3 feet from the cleanout.
5. Put one of the attachments on the tip--I use the root cutter for most jobs. It's U-shaped. The spade bit is also good, but as this is on a rental I want to see if my tenant is to blame, because then I charge them for my time. There is also a corkscrew/spring attachment, but I don't like this one.
6. Start feeding the metal spring down the clean out by hand. Don't use the motor yet. When you have pushed the spring as far as you can by hand, stop pushing.
7. Adjust the spring so that there's a little slack, but not too much as the spring can form a loop and catch your hands, fingers, or just smack you. The spring can also catch skin, cloth, or your gloves in the grooves, so treat the machine with respect. Then step on the foot switch and hold the spring loosely while the motor turns the snake. Do this for about 15 seconds to one minute. After some practice you'll be able to notice differences in the sound of the motor.
****Safety Warning**** If the snake loops up, you take your foot off the switch. Then put the machine in reverse. Tap the foot switch to unwind the snake.
8. Repeat steps 6 and 7 until the water has drained out of the pipe or you've reach the end of the snake.
9. Put the snake in reverse, but don't push the switch unless you need to.
10. Start pulling the snake back and load it back into the drum.
****Warning**** The snake is a spring that can fling the effluent on you and the end has a tend to whip if you pull it out too quickly. Anything stuck on the end of your snake might get flung at you. Use your imagination.
11. I like to run a hose down the drain AFTER it's been unblocked.

If you're on a septic system and the clog won't come out, your septic tank may be full.
Hope this helps. If you're afraid to do this yourself, my buddy or I will do it for a couple hundred dollars if you're in the High Desert. :-)