Here are some helpful videos for coaching technique and positioning:

Hitting:  https://www.youtube.com/watch?v=FYP2txnZm4I

Hitting (set, load and fire):  https://www.youtube.com/watch?v=fG7020cZM1Q

Infielding position:  https://www.youtube.com/watch?v=8V_VJVi3268

Outfield (catching flys):  https://www.youtube.com/watch?v=UYItjZ8hPg0

Cutoff from Outfield:  https://www.youtube.com/watch?v=rjYLK2BA4vU (IMPORTANT)

1^st Base (picking balls in the dirt):  https://www.youtube.com/watch?v=_fj8UXEBP2g

Catcher Stance: https://www.youtube.com/watch?v=WyBn9oV7iK4

Catcher Throwing to 2^nd:  https://www.youtube.com/watch?v=RmlsQPV4OGs