See this thread on here. http://www.crappie.com/crappie/south...ing-questions/

After doing it awhile, you will learn quickly that all the variables involved (boat speed, length of line out, weight of lure, ability to interpret sonar, etc.) make a huge difference in your success.
I suggest you start with 1/16 oz jig/grub combo at 1mph with a full cast behind the boat. That will put you in the 6-7 foot deep range from my experience. If the fish are deeper, go heavier, longer, slower. If shallower just the opposite. ALWAYS troll over the fish. Never under.
Practice makes you better, never perfect!

I hope this helps you get started.

Chris