It's a piece of cake but I hope an endodontist is doing it and not just a regular dentist. Endodontists do root canals all the time and know the best methods where as a general dentist doesn't specialize in them and while they know how to do it might not do them as proficiently as a specialist.
First thing, don't take anything that contains aspirin as that will thin the blood and there will be slight bleeding. I don't see a problem with taking ibuprofen but to be on the safe side ask.
Now what to expect. First he will take an x-ray of the area so they can see the root pulp and canals in the tooth. Then you'll receive a shot of lidocaine mixed with epinephrine. The area is usually numbed first with a topical ointment and a good endodontist can administer the shot without you feeling a thing. One thing to be aware of - the medication does have epinephrine(or an equivalent) which is to slow down the bleeding.
If this gets into the blood stream (which it's not suppose to) you will suddenly have heart palpitations and slight tremors but it only lasts a second and the endodontist will know if he's gotten it into the blood and will prepare you. To be honest, that was the "worst" part of the procedure for me.
After you are numbed you will have a
dental dam put into your mouth. It's basically a piece of latex that covers the inside of your mouth and prevents you from swallowing any of the icky stuff and also isolates the tooth to be worked on. Next the tooth will be drilled (feels no different than having a cavity filled) The endodontist will ask you if you feel anything and
if you feel anything unpleasant he will numb the area more.
After the tooth is drilled he will use thin needle looking implements to scrape out the root. He'll probably refer to the x-rays a few times because it is possible that the tooth will have an anomolie such as additional canals or have 1 canal that spilts off into 2 and he will need to pull out all the roots. As he is doing this you'll have the suction tube in your mouth to catch all the debris. Remember, you never have to worry about swallowing water or any of the tooth drillings because you're protected by the dental dam.
After he has pulled out all the roots he will pack the canals in the tooth with an antiseptic packing and then fill the drilled hole with a temporary filling.
This is the end of step one

After the procedure you should have no pain other than an aching jaw from having to hold your mouth open so long and a bruise around the tooth that was worked on. The bruise is from the clamp that surrounded it when the dental dam was used.
Usually about 2 weeks later you will return and the endodontist will once again give you a shot to numb the area (this time he does not have to use epinephrine)and place the dental dam in your mouth. He will drill into the tooth again, pull out the antiseptic packing, scrape the canals once more, and then fill the canals with
gutta-percha filling which has sort of a rubbery consistency and faint taste of cinamon. On top of the filling he'll probably use small cotton pellets and then fill once again with a temporary filling. He will send you to your dentist to have him do the crown.
All in all this should not be a traumatic experience for you but I can certainly understand your fears. I was a nervous wreck when I had one done last year but I realized I had worked myself up over nothing. After each visit I was able to go straight back to work. I was just a little sore but certainly didn't need any pain pills and didn't have any throbbing pain. I was just instructed to take ibuprofen for a few days afterwards.
If this hasn't helped to set your fears at rest you can always request that the endontist use some nitrous oxide on you. I've never used it but I did ask about it but when my endontist told me I'd feel "high" when using it I said "no thanks" and he agreed I would not be a good candidate because he could tell I was not one to "not be in control" lol
I think you will have no problems with this and when it is all done and over with please come back and tell us all about it
