I just added a tutorial for digitizing scanned sketches. I hope you find it helpful if you're interested. I also hope it doesn't have too many typos or errors. Please give me a heads-up if anything jumps out at you.
Also, I apologize for the heavy load time for the main page while 4 out of 7 pages of the tutorial sit up here, images and all, waiting for me to make some new entries and push them down and out. If it hasn't been raining, it's been full moon time. Can you tell?