I am often asked the question, 'what is the best way to get my arm in shape?'. The answer is a throwing program. 91's is my personal favorite throwing program.
You start playing catch for 9 minutes at 60ft, then take a 4.5 minute rest. Next you play catch for 8 minutes. By doing the 9 min catch, rest, then 8 more minutes, you have completed a "98". The goal is to work all the way up the chart until you can complete a "91" (45 minutes of total throwing, 22 minutes rest). Each section should take you one week. The entire program takes 8-10 weeks to complete. I recommend starting in early august so you will have arm strength through the fall and into spring.