The Sheraton is certainly the most convenient at Schiphol and its not a bad hotel at all (just an airport hotel like many others). You may also want to check to see if the brand new Hilton will be open by then? If it is, I would book that one as new hotels are usually super.

Restaurants - depends what you are looking for? I've had 3 meals at Vinkeles in the Dylan Hotel which is in the Jordaan - a short walk from Centraal station. It has a lovely atmosphere, good service and an interesting menu (French and International) and although we were there for business dinners, I did see someone proposing and getting engaged one evening - which was lovely as we all celebrated with them. I'm sure if you told them you'd just got married they'd pamper you!

There are restaurant reviews on the web so you need to decide what sort of food you want to eat really and start there (other forums on FT will be able to help more)

Easiest way into Amsterdam is simply to catch the train from Schiphol plaza - you can even go for first class if you want as the difference in price is minimal but its entirely up to you - wherever you sit on a Dutch train its better than a UK one. Its so easy to buy the ticket and there is really no need to take a taxi as its super convenient too. After a 15 min trip you end up at Centraal station and from there it should be a beautiful stroll around the canals.

Just has a thought - there is a nice rooftop bar at the Doubletree Hotel just a 4 min walk from Centraal - might be nice to go there after the meal for a drink before getting the train back to the airport? You could stay there too as its fairly new - their suites have great views of the city.

Or book a romantic ride around the canals to see the sights?

Hope that helps. Shout (or pm) if you have any other questions?