P.P - i freelanced in amsterdam for a year or so but i had a dutch friend who sorted out all the legal stuff for me - she was an accountant and just told me where to sign the forms. find an accountant.
i'd recommend working full time for some different people first - its disheartening breaking something on a freelance job and you won't get asked back - break it for your fulltime employer and you won't make the same mistake again. freelancer's are used b'cos they don't need training, hopefully they don't even want a cup of coffee, they're just gonna sit down and do exactly what you tell them to do, possibly tell you a better way of doing it, and doing it bloody quickly.
i don't think you need a flashy website, more important is proven understanding and word of mouth recommendations. you can spot a blagger as soon as they sit down.
just remember, its a small world out there, you'll bump into the same people over and over again. they'll remember you for what you did for them the first time...
good luck. zeker veten!