Almost done
I'm actually just about finished with this project and thought I would add my 2 cents to Mitch and Geoffs comments.
I used a kit from Boatleather and it was great to work with. I was able to talk to a guy from boatleather at the Chicago Strictly Sail show and they were very helpful. I got to watch him put a cover on a wheel at the show. Practice obviously helps, it went on quickly. He set me straght though and told me my 42" wheel would take me a long time. If you can afford it, it might be worth it to send your wheel to Boatleather and have them do it.
Don't underestimate the time it will take and how sore your fingers will get.
Practice the three stitches you'll need to know. The starting stitch, the herringbone, and the tie off stitch. If you are comfortable with the start and end you can use shorter lengths of thread, which seemed to go faster than trying to pull lots of length thru each stitch.
I mounted my wheel on a sawhorse using a piece of a broom handle and it worked well. I used a clip on light to provide good lighting, which you need. My cover was buckskin suede and sometimes the pre-punched holes were hard to see. Good lighting was critical (it couldn't be my age and my eyes getting worse, I'm sure).
The end result looks and feels great. All of Mitch and Geoff's comments were right on. The boatleather kits use a different stitch than Mitch used.