As I speak, I am using Dragon naturally speaking. If you run across the word that it can't spell, you click on train tab, spell it out, then pronounce it and it will remember that word in its database.
I'm highly impressed with this program, and enjoy it very much since I don't like to type! The commands are very simple and very friendly to use. I didn't type 1 word here, I just speak it and it types it.
Hope this helps!
Gary