Don, I got my Ace 350 back in November, but really didn't start "learning" it until April of this year. You're digging the right stuff, but man you need to dig EVERYTHING in the beginning! This is the only way I was able to learn what my 350 was telling me.
Now, most every signal that comes back to me, I already have a pretty good idea of what's going to come out of the ground even before I dig it. Occasionally I even surprise myself and find a silver coin or ring instead of a beer cap!