Hi Dave,
LOLserver put together a great Uneven Lie Tutorial thread here which may have what you're looking for. (I think Icon even pinned it for us in the Game Tips forum).
There's also a good thread here.
Personally, I gauge the slopes by experience rather than trying to time them... but I know that Cerino (CerinoDevoti) once described his method relating to dots moving (which I failed to understand, lol), but right now I can't find it. Perhaps buried in one of those threads...
Edit: aha, got it: page 5 halfway down, Cerino's post.
Also, I've said this before, and I'll say it again: I found the best way to learn Unevens was with Starter Clubs and balls. First off, it's cheaper, there's no risk of losing balls while you learn. And secondly, using Starters is how we all learned to play this game in the first place, so it's the best way to give yourself a base-level to understand it from.
And now, a shameless plug :)
If you want to try Uneven Lies with Starters competitively, join in with our Tough-It-Out tournaments every month (in a Tour that parallels the main WGT Virtual Tour).
This month's event @ Bethpage starts today!