Been to Amsterdam once when I was in college. The Red Light district is a must of course. The Mrs might not appreciate it but at least walk through the street. Literally, the whores sit in their windows looking out at you. And yes, there is a red light. If it's on, they are "busy" with other clients. There are live sex shows as well.
You also may want to tour Anne Frank's home. It's a big tourist attraction. Personally, it was a little boring for me but there's an awesome pub just below that will ply you with Heinekens. You should do the canal tour also. They will take you down through the cannals, which criss-cross the city. Beautiful architecture.
If you can manage it, take a bus (not very expensive) to Brussels. If memory serves correct, it's about a 4-6 hour drive and you see some beautiful country, including the windmills. La Gran Place is the place to visit in Brussels. And the Mannequin Piss - the famous statue of the little boy peeing. Make sure and sample the space-cakes for a good high. Also try the mussels in Brussels. I think that's a popular dish in Brussels.
Most importantly, don't forget to bring back some seeds!!! And mail me some, beaaaaaaatch. Please?