Question:
There are more than 300 marijuana and hashish selling coffeeshops in Amsterdam. So how do you know where to go and what to order?

Answer: Don't want to throw cold water on your plans, but I did read recently that all coffee shops were to begin demanding I.D. from customers, as they were only to sell to Dutch nationals. Foeigners were to be excluded. This may have been a hoax, but it may be worth bearing in mind.