I would look at a couple of issues of the magazine Coastal Living plus do research on this site. Personally, I love beach homes is pale palettes of sand and very, very light blue with splashes of color in accessories. What a fun project. Good luck.

Use loads of white, paint some ceilings with these colors and walls white, and colored walls in some rooms with white ceilings.

Here is a link to a site with designs by Sarah Richardson. IMO, she does such a great beach style. Always looks so fresh and crisp, but so inviting! http://houseandhome.com/design/photo-gallery-sarah-richardson-designs