Getting Started

Hi, Our community just opened a new pool and I am psyched! I have been swimming a 2-3 days a week now for about 3 months and have no problem (except running out of time) swimming 1750 yards freestyle. (I have been measuring goals in miles). Currently my goals are fitness related. When i was a kid, I was on a swim team and loved it but have forgotten the lingo, the culture, how to work out, etc. I'm just swimming on instinct. So now that I have a pool to swim in :), I am looking for resources to learn how to fine tune technique, put together workouts, know what times are reasonable, setting goals, etc. Also, I am in my late 40's and recently have become concerned of what I am doing to my shoulders. As I swim I notice that i am favoring my left shoulder as the joint hurts when I pull hard through the water. My solution has been to alter strokes, etc. But still concerned. The last thing i want is an injury that will affect my ability to swim. Thanks in advance for your thoughts!