I just finished reading the Paper Jacket by Paul Mathews. Excellent book.
This is kind of neat because I get the feeling there is still lots to be learned on this subject. Although Paul managed to write a small book on the topic, there's lots more to cover.
There are two pieces of advice I've got from this site, which is also in Mathews' book that were really key.
1) You can use your normal cast bullet mold to cast a pure lead bullet. Then just wrap it up in paper and run it through the sizing die after it's dry. This was an awesome tip because it made me realize I could get started with tools I already had.
2) The next piece of awesome advice was to load with 100% density. My first attempt with paper patches I had no leading, but no accuracy either. After loading some high density loads, the groups shrank up real nicely.
That's about it for my experimentation. Next I want to try patching a 125 grain bullet in my .357 Lever Action. Then, I'll see if I can fine-tune the 158gr bullets to get a tack-driving load.
I think the pistol magnums have a lot to benefit from paper patching. From either rifle or pistol, the magnum velocities fall between 1200 fps and 2200 fps. Below 1200 and leading problems taper off, making jackets unnecessary. Above 2200 fps and a soft lead bullet begins to come apart from atmospheric resistance, and excessive spin.