UKIE ! All good questions Its great you are interested in this! I wish you were nearby so I could show you how much of this is done.

OK here are the short answers:

1. Tileprint.

2. Tracing paper or use Tileprint's select tool to just print the parts you need.

3. The tool depends on the material being cut. For cutting sheets less than a 1/8 inch thick a few slices with a modeling knife will do. Any thicker A saw would be better.
Ribs are usuallly cut in rectangles which we will call blanks, one for each rib. Then the blanks are stacked together with a template on each end, then you use a saw or knife to whittle away the larger cunks sticking out till you get close to the template edge. Then sandpaper the rest. You have sandpaper right? You will definitely need sand paper.

4. Sometimes... Other times you use the specified size wood indicated on the plan and sandpaper this to its proper shape. Oh! Did I mention you will need sandpaper?

More about Tileprint here:
http://www.rcuniverse.com/forum/m_1369249/tm.htm
Tileprint is only second to Windows to me.

I hope some of this helps!

Robert