Keep clear of Newquay - it does not represent Cornwall.
If you are beaching, go for the North Coast - however many of the villages are not that attractive but good beaches such as Portreath or Perranporth. St Agnes is nice. Anywhere around the north side of Padstow (St Enedoc) is nice but full of Londoners. Further up there is the Doc Martin village of Port Isaac and that is nice.
Further down St Ives is really nice and much improved with the Tate Gallery which has spawned a lot of nice smaller shops/galleries and some excellent restaurants. Great beaches with Porthmeor, Carbis Bay, Porthminster and even in the harbour. Some lovely countryside (wild) in West Penwith (St Ives to St Just and Lands End. Loads of hotels - an inside track but not near the beach is the Tinners Arms at Zennor. Also and inland and central and esay to get to is my local, The Plume of Feathers at Mitchell. Very nice pub just off the A30, comfortable and very good food. It's sister hotel is the Lewinnick, unfortunately in Newquay. The reason for dissing Newquay it is very much surfer and drunken teenager country.
http://www.theplume.info/