I've been to Amsterdam more times than I can remember, including yesterday. There are a lot of coffeeshops, and most of them suck (yes, I'm picky about weed), however, there is world class weed to be found if you go to the right ones. For a heavy, tasty indica go to Green Place. The budtender knows his buds, so don't be shy to ask him what he recommends. I bought a gram of White OG yesterday, and I'm very impressed with it. Classic OG taste, and a very intense indica stone. Great for pain relief and insomnia, and appetite stimulation too, I suspect. Before, they used to have Lemon OG which wasn't quite as strong, but absolutely reeked of lemons. Really fun to smoke...
Coffeeshop Amnesia is also one of my few favorites. Again, great weed (especially sativas) and great food. They got nachos with various toppings, mini pancakes, ice cream, pitas, and i forget what else...also some overpriced smoothies...Good place to hang out, eat and get baked...I didn't like the music though, and it was kinda loud...This one is reasonably close to the train station, so that's where I go to get baked right before getting on the train for the way back.
Besides coffeeshops, there's other stuff to do in amsterdam. There's a botanical garden with some of the world's oldest greenhouses, for example...lots of museums too (van gogh, cannabis museum, sex museum, etc...) Also lots of fun headshops and smartshops. If you want those, go to Warmoesstraat. Conscious Dreams always has interesting stuff. Also check out Nieuwendijk...one end of the street has some fun shops like Full Moon.
Always pay attention to your stuff, or you might get robbed...also don't even talk to street dealers, it probably won't end well...Amsterdam is fun, but also very crowded and dangerous, so be careful.
As for the cup itself, I must say that after going there twice, I'm a little disillusioned...it's all too commercial for my taste...last year I didnt even go because they raised the entrance fee for the expo from 30 euro per person to 50...There is some fun stuff to see at the expo, but you can see it all in less than a day. They do give out plenty of free samples though...
Let me know if you got more questions