I am living in a very old house, and it has finally started to fall apart. The toilet and bathtub both need to be replaced, and I wanted to try to do it myself because I really can not afford a plumber at this time. Is there anywhere that I can find the step-by-step process to accomplish this - like "Plumbing for Dummies"?

It would help to first read a basic plumbing book from the library. Some of the best DIY help books are those Time/Life ones, or Sunset. Your library probably has them.
Online:
Yahoo Groups DIY
eHow (variable quality, some of it is terrible)
YouTube, just search 'plumb toilet'
The folks at Home Depot, etc. are often very knowledgeable in the department you find them in, and you can buy all the parts there. You may be going back and forth, not knowing what you have at home to describe to them. One way is to buy all sizes and return what you don't use.


Before anything though: Turn off your water main and open all spigots and make sure the water stops. It may be so old that it won't hold back the water, and you should call a plumber for that. Some towns still pay for anything that is on the street side of the meter, but many don't now. If you don't want to pay for a new main valve, you'll have to find one further along the water supply that does stop the water.

On a 1-10 scale replacing a toilet is a 2 or 3 but a tub could be an 8-9. How much handyman experience do you have,any previous plumbing?

Plumbing for Dummies, I like that. Some of our help answers are probably Dummies for Plumbing but we try! Lots of on line help, library, my local Goodwill always has a big supply of self help books at .50-$1. Toilets are pretty easy, as Bob says 2-3, the whole toilet is held with 2 screws and nuts, it's lifting the toilet and getting the wax ring right that is harder. Tubs are usually terrible because of the weight and confined space. A steel tub is inexpensive but getting it in can be a hassle without cutting open walls. Mobile home tubs are smaller, usually composite and are an easier retrofit.