Werner has the following suggestions on pitch count. She is much more conservative than Bristow. In a perfect world, with exceptions for weekend tourneys, she believes the following pitch counts would be the best, when possible.

10U - 60 per day with one full day rest after each of these days. A pitch includes anything where your arm is spinning. 60 every other day equals 240 pitches per week.
12U - 70 per day, every other day (280/wk)
14U - 80 per day, every other day (320/wk)
16 - 90 per day, every other day (360/wk)
18 and older - 100 per day, every other day (400/wk)