"How to get to Dinard?"
For our recent visit we took advantage of a (very) cheap flight from Stansted to local airport of Pleurtuit, 20 minutes from the beach. Flight time under an hour. Keep an eye out regularly for good prices on this route.
Otherwise by boat to nearby St Malo or the usual car / ferry / train / coach etc.
Personally I recommend visiting out of season although if you enjoy water sports you will love it in season. Little ferries that take you across the River Rance to nearby St Malo stop running at the beginning of October, which is disappointing as arriving at St Malo this way is just magical!!!
"Where to stay in Dinard"
Try chambres d' hote (bed and breakfast) if you fancy a change from hotel accommodation and a closer glimpse of local life. You could also stay in St Malo or outside Dinard of you fancy a rural setting.
"What to eat in Dinard"
The local speciality is the "galette" which is a large pancake made with black flour. We had "la complete" which is stuffed with cheese, ham and an egg. You can have a "complete champignons" which has mushroom as well as cheese, ham and egg or virtually any filling you like... savoury, followed by sweet! Miam!! Should be washed down with local cider, although the observant of you will have noticed that here we are drinking beer!! Oh well!!