Sallenelles in on the D514 which runs along the coast. Sallenelles is between the Caen-Ouistréham motorway and Dives/Cabourg. You can also come from Troarn, Hérouvillette and Amfreville.
You can cycle to Sallenelles from Amfreville or Ranville (the roads are quite quiet), from Bénouville (take the foot path along the Orne, or from Merville-Franceville (there is a cycle path along the main road which is separated from the road by shrubs, or there are numerous paths cutting through the dunes and the bay which are easily done on a bike.
You can take the Bus Verts line 20 which runs from Caen to Deauville and Honfleur. Note they don't all stop in Sallenelles.
The whole village is easily manageable on foot. The bay can get quite muddy though, so don't wear your best shoes.
Walk around the bay: Although Sallenelles is a very nice village, almost everybody who stops there is there to see the bay or the Maison de la Nature.