KLM has three lounges in AMS, one in the Schengen area and two in the non-Schengen area. All three can get very crowded (but are reasonably nice when they're not crowded). Reasonable selection of drinks, but no food other than nachos, mini muffins and cereal bars. There is broadband Internet access but you have to pay for it.

If you are a non-smoker avoid the Schengen lounge like the plague. All three lounges have smoking areas, but whereas smoking areas in the other two are behind a screen the one in the Schengen lounge isn't and the whole lounge has a smokey atmosphere.