Day trip from AMS to Brussels and Brugge

Do you mean visit both Brugge and Brusels in one day????? If so, it's not practical. Even just visiting Bruges would mean a 3.5+ hour trip one way. If possible spend at least one night in Belgium. This site will give you schedules and fares for the entire journey: http://www.nshispeed.nl/en Some connections use the Thalys high-speed train. The Thalys uses airline style pricing so the sooner you book the cheaper it will be (90 days allowed).

I'll be spending an over night in Brussels, waking up and then going to Brugge. I did check out the Thalys. Is that the fastest/best option? I see there are buses via EuroLines, but I don't know if it would be worth it. I'm guessing 90 days in advance would knock the price down pretty much on a Thalys ticket?

The savings are significant when booked 90 days in advance; fares can be around 30 Euros. If booked at the last minute fares can go up to 100+ euros.

Do you mean 30 Euros each way on the high speed train?

30 Euros one-way.

Thanks! The first class does look tempting!

First class isa waste of money on the train if you are on a limited budget, as you've said in your posts. It's not like a plane. Cheapest opion is to buy tickets early or take the bus.

There is a another option that's cheaper than a full-price Thalys ticket, but not necessarily less than a discounted fair. And much slower. From Amsterdam, buy a ticket to Rosendaal on Dutch rail (NS, or Nederlands Spoorweg). At Rosendaal, the border station between Belgium and the Netherlands, buy another ticket on Belgian rail to Brussels. You will need to ride a slow commuter train to Antwerp, then change to an intercity train for the short ride to Brussels. You might be able to buy the whole leg of the trip on one ticket, but you would need to explain that you don't want to ride Thalys. And just to emphasize again, this option is only cheaper than the full-price Thalys ticket, not the advanced-purchase discount.