Hi
If you're planning on going to Holland, I'll suggest going on Norfolk Line from Dover to Dunkerque, it's about a 2 hour sailing time and it's not 'as busy' as say Calais or Boulougne - I went june 2005 to help my mate move back over from Amsterdam, drove right up the the barriers, showed my pre-book and was waived through, I could've purchased right there and it wouldn't have taken more than a few mins - but I side with the suggestions to pre book.
5 mins max in France, then you hit into Belgium, head towards Antwerp, then take the A1 up towards Utrecht.
One element of caution - If you are heading this way watch out for the stupid Utrecht one way system! I thought I was doing ok until I called my mate and he started laughing as I'd taken the Longgggg way round!
I did have my TomTom GPS but as I was fiddling around with another program, my GPS signal kept dropping every 2-3 minutes, had I taken the other direction in the 1 way ring road thing, I would've saved around 23-30 mins !
Cheers!
DtM! West London & Slough UK!