CZZB is a good field to fly from in terms of learning all about traffic and tough nut controllers - they don't let much slide. It's busy, but I've never had to sit on the ground for any long (read expensive) amount of time. Great experience for learning how to talk on the radio. Many flight schools to choose from, but PROIFR looks to be the most professional and efficient. Check out Centennial - I think that they have a Dutch instructor, at least that is how it sounds on the radio.