Will, all of ML�s suggestion are are on the mark - keep it simple.
The easiest way to determine the amount of backing is to wind on the fly line first and then the backing, until reel is near full.
Then wind the backing onto another reel, or sometimes I use a large empty line spool.
You�ll have to reverse the process and then tie the backing to the reel spool with an arbor knot.
Dacron backing is adequate for most reels but if you need more backing when you graduate to ML�s tarpon reels , consider using gelspun backing for more reel capacity.
A full reel provides faster pickup, but for your pond reel, it is just a place to store your line.
I agree with ML on a heavy butt section, and mono for leaders. I use a minimum of 12# and sometime 16# test to land the fish quickly if fish is to be released � otherwise fish caught on light tackle seldom survive. Use lighter and longer �tapered leaders/tippets for extra clear water �otherwise shorter the better.
A heavy butt section not only helps to �turn over� the fly, but minimizes line twist when casting poppers and gurglers.
�Google up� Lefty Kheh casting instruction video � he�s the best.
I�ll try to find it for you.
Stay away from the �classic� casting instructors - keep it simple.
Probably more than you wanted to know � good luck.
George Glazener