Well I was fortunate as a lad to have the guidance of an old taxidermist who worked in all the big museums in Scotland. This is how he showed me to do it.
If it is a pelt that you are after
Stretch out the skin and dry on a board or frame (use map pins)
Once dry use a paint scraper with the edges rounded off to scrape ALL meat and FAT-this is the hard bit because if you don't your pelt will stink and rot. Finnish off with sandpaper if you can't scrape any off.
Soak your pelt in BORAX over night (a mixture of borax and water)-this will clean it
Then rub pottassium nitrate (Saltpeter-you may be able to get some at your local waterworks as they use it to filter/clean water) into the skin, this will preserve it.
Dry it out by pegging again. It will go stiff as a board. Once it is stiff all you need to do is find a a washing pole or tree and rub it back and forward like a fan belt and it will soften up eventually-you can add lanolin (I've used vasoline at times) to help the process (essentially mechanical chewing!)
This will work as I made a pair of welly boot liners once out of them.