Just to clarify a few points:
There are no Honey Buzzards at the Wensum Valley watchpoint this year. The only sightings are from the Swanton Novers site but appearances are erratic - you could stand there for hours and not see them, or get lucky quickly, it depends on how much time you have to spare.
Pensthorpe is mainly for captive birds (wildfowl and more besides), it does have a wader scrape but personally wouldn't bother visiting as everything there can be seen elsewhere e.g Cley and Titchwell.
Not sure when you are visiting but note that from Mon 26th July the main path at Titchwell is being closed for on-going flood defence works so there will be no access to the scrapes.
There are no Monties at the site north of Kings Lynn, there is one site in Norfolk but unfortunately its location can't be specified on an open forum. The bird referred to at Minsmere was just a passage bird that is no longer present.
You'll be hard pushed to see Nightingale now that they have stopped singing, although you may stumble upon one, again it depends how much time you have available to look. Nightjars are still churring at present so you'll hopefully be in luck with them as long as you've got a specific site lined up. Woodlarks in the Brecks but again you'll need specific site as to not waste too much time looking for them.
If you do want to go to Blakeney Point for the seals and terns, as mentioned earlier, you'll need to go by boat from Morston Quay. Trips are only at high water so you'll need to check sailing times to tie in with when you'll be in the area. Common, Sandwich and Little Terns can all be seen around Cley. No Roseates and you'll have to be very lucky to pick out an Arctic.
Med Gulls can be encountered at either Cley or Titchwell but usually just drop in for a while. Cetti's Warblers can be encountered at both sites too and wader numbers are building up at the moment e.g Wood Sands and Little Stints etc have started to pass through plus the usual Norfolk 'specialities' Avocet, Bittern, Bearded Tit, Marsh Harrier etc.
On the rarity/scarce front there is currently a Ferruginous Duck at Minsmere, Buff-breasted Sandpiper at Titchwell, and also there are 11 Spoonbills at Cley. No Quails around at present I'm afraid.
Lakenheath is worth a visit, good for Bittern and Hobby, but as already mentioned you could be in for a wait for anything else there (i.e Golden Orioles, Cranes).
As James said your best bet is to grill a few locals when you are up here to get some up to date info with specific sites and directions otherwise you could waste a lot of time looking for species that are either not present or take time and a lot of luck in seeing, especially without good gen.
Hope this helps, and didn't sound too negative in places! If you've never been Norfolk is an excellent destination with lots on offer and I'm sure you'll have a great time.
Simon
