Getting back into it

I'm rather new to the BT forums but have enjoyed the site for some time.  I am almost 23 years old and have 2 triathlons under my belt.

I decided to try triathlons on a whim.  A friend of mine did one and suggested I try, so I did... and LOVED it!  However, an old high school injury flared up while my swim training.  I was able to hold of a shoulder surgery till after both of my triathlons, but I am just now able to start getting back into (over a full year later).

I have remained active, and have maintained a decent base endurance.  I've been an athlete my entire life, so I am by no needs starting from ground zero.  I have been running the past month, and have been getting back into doing some lifting exercises to prepare my shoulder for swimming again.

My question is any suggestions to help me get back into my triathlon shape of last year quicker.  Also any suggestions in avoiding injuring my shoulder again would be extremely appreciated!

Thanks all!