Shetha helped me realize what the problem with the sleeve was. I was thinking that I had to mark every 12th stitch anew on every sixth row, when in fact, once I marked them the first time I should have left them alone! Duh! So now, the sleeve is progressing nicely and is almost done. The front and back are being blocked. I am already looking for a new project to start.
I think I will buy the Sweater Wizard and Stitch & Motif Maker software. I downloaded the demos and played around with them and they're pretty cool. The Sweater Wizard has a choice of different necklines and sleeves that you can put into your pattern and then further customize. It creates diagrams of the pattern, as well as text directions. I want to start making my own patterns, but I'm a bit intimidated, and using this software seems to be a good way to transition into that. At least for the way I think and do things. I feel that I could sketch out what I want and then actually create it using the software. Once I see that translation several times, I think the overall process will be easier for me.