Hi Paul,
Some previous threads here:
TMP link
TMP link
TMP link
TMP link
My faves (Absolute unmissable must-sees are marked with * and free-to-enter places are marked +):
British Airborne Bridgehead:
Pegasus Bridge*+ (including Cafe Gondree* & Memorial Pegasus Museum*)
Merville Battery*
Ranville War Cemetery+
Sword Beach:
Strongpoint Hillman+ (you can go in any time, but they open the bunkers on saturdays)
The Grand Bunker Museum, Ouistreham
Hermanville-sur-Mer Beach+
Juno Beach:
The Canada House, St Aubin-sur-Mer*
Courseulles-sur-Mer
The free cider-tasting stall on the main road to Gold Beach…*+
Gold Beach:
Ver-sur-Mer & the Green Howards' shed+
The Mulberry Harbour viewpoint between Asnelles and Aromanches.*+
The Musee du Debarquement, Arromanches (and the town itself).
Longues-sur-Mer Battery*+
Bayeux City*+ (including the Tapestry*)
Bayeux War Cemetery*+ (park next to the museum, though the museum is no longer very good)
Omaha:
US Cemetery*+
Strongpoint WN-62*+ (Colleville-Plage – walk down from the cemetery car park – the bunkers and trenches are below the 1st Division memorial pinnacle)
Dog Beach*+ (western end of Omaha Beach)
There are lots of museums around here of varying quality, including a big new one that I haven't had time to visit.
Pointe du Hoc Battery*+
Utah:
Ste Mere Eglise*+ (including the Airborne Museum*)
Dunes de Varaville bunker complex (park at the Division Leclerc memorial Sherman and follow the dunes north)*+
Utah Beach Muesum, La Madelline*
Brecourt Manor (tricky to find if you don't have a map or guide book – follow the road from Utah Beach to Ste Marie-du-Mont and turn right at the Dick Winters statue on the crest of the hill. After 200 yards you'll see a memorial on your left. Park there and follow the lane next to the memorial for 200 yards until you reach the farm – the field where the battery was is through the gate on your right; Winters attacked from the far side of the field)
If you have the time, there are plenty of inland sites to visit, though you need a fair bit of knowledge (or a good guide), plus good maps and/or guide books.
I can e-mail you the handouts and itineraries I use for the cadet tours if you pm me with your email address (beware that some are large files).