Alison, you will be spoilt for choice for food. The BBQ seafood at the night markets is excellent value and great taste. We also ate at Jasmines Restaurant in Selakam Rd (a small soi near the Hilton Hotel which was recommended to us by emdee) the Red Curry Duck was amazing! Some other small places that I'm not sure of the name - we tended to stick with the smaller family run places.
We had a treatment at Anama Spa Tanawit Plaza on 1st Floor 64/1 Amnuaysin Rd,Hua Hin, it was heaven. A little more costly than the massage places all over HH but very luxurious without the luxury prices of the hotel.
We booked a tuk tuk for a few hours (hindsight I would rather have been in an a/c car for the trip back) we went to Wat Kamphaeng Laeng - Khmer ruins, Phra Nakhon Khiri - Palace on the Hill and Khao Luang Caves.