Which airport you land at depends on where you are coming from. Hewanorra is the main airport for larger planes and it is located at Vieux Fort at the southern end of the island. The airport at Castries is only for smaller planes. I have only heard of people coming in there from San Juan.
According to their website (www.coco-resorts.com
), they are about 200 yards from the beach.
You can see the activities I did in my short trip report, which is the next post down. I also mentioned the various restaurants in Rodney Bay where I ate.
I hope this helps and that you have a great trip. Don't forget to post a trip report when you get back.