A couple of things to make sure you avoid (things I hate about local fields)
They don't drain.
They aren't enclosed (each game there is different out of play lines)
The dugout entrance to the field is too far away from home plate (as in up the line, annoying to have to toss bats out of there)
The sun at its lowest point is right in my eyes (orienation of the field).
A bullpen outside the field of play
I'm sure the books will help you out. Now if I was a kid, here's what I'd want in my field
In-ground dugouts
Lights
A Clubhouse underground entering the dugout
