I'd suggest using a Leave-in conditioner on your hair before swimming as you mentioned.
Also, after your swim you should use a shampoo like Nexxus Aloe Rid (it's a clarifying shampoo and it's good for removing chlorine, etc.), you can follow that up with your favorite moisturizing shampoo and perhaps a Protein Reconstructor followed by a moisturizing conditioner.
I know it sounds like a lot. Maybe you will get more input from some of the other members.
Hope that Helps!