Looking for step-by-step instructions, with illustrations if possible, on hanging a door/door frame (interior). Can anyone help or point me to a web site that would have an answer?

Don B,I hope I can be of some help.I don't know where you can find info on the web on installing doors,however the Home Depot publishes a excellent book for the DIYer-"Home Improvent 123".It has a whole chapter on Doors & Windows w/step by step instructions as well as illustrations.I believe you may be able to order it online too.Their web address is www.homedepot.com.
I would recommend you going w/a prehung unit as well to simplify the process.It comes hung on a frame as well as being pre-bored for a doorknob.You can also buy pre-mitered trim to go w/it but BEWARE.If you have not installed the door perfectly square it will not fit right.It's a coincidence that you ask because I just finished doing my downstairs bathroom door tonite!Well Don good luck w/your door!

Home Depot makes enough money. Just go to the local library. They should stock many DIY books on most any subject.