Hi Cookie
Sorry for delay in responding, 3rd day back at work :-( and it's carnage after a month off!
Firstly I'll direct you to Swift2008's thread where there's a bit of info on things to do etc...which you may find useful.
In addition to that I'll tell you a bit about the site itself.Firstly getting there, follow the motorway signs to Interlaken and go straight there, don't be tempted to go to Thun itself and take the road round the lake it looks very pretty on the map but is a caravan killer of a road in parts! When you get to Interlaken head for Interlaken West not Interlaken Ost, that will put you in the right area. On some of the signs are some camping signs with numbers for eg. camping 1-5 or camping 6-8. Manor Farm is number 1 so head for that, you will see what I mean when you get there.
The site itself can be quite cramped so if you value your privacy at all take a windbreak. An inflatable boat is a must in my opinion, we bought one out there and had great fun with it on the lake. Mind out for the swans with the young they can be a bit vicious but tend to get used to you after a while. You will need to hire an adaptor for the electric hook up, they will offer you this at reception anyway as theirs is a funny 3 pin affair the like of which I've never seen before.There is a refundable deposit of 25 francs for this. Amenities at the site are great, typically clean to the Swiss standard, showers will blow you off your feet! the best I've ever seen anywhere in the world! There is a washing room for the clothes and the cycles take an hour and cost 5 francs as will the driers. You find this under the reception block in the basement. If you are planning to hook into the water supply (each pitch tends to have a drain in the ground somewhere near it - just lift the cover and pop your hose in - then make sure you have 10 metres of hose and waste pipe with you. You may not need it all but we did, also make sure you have a radiator bleeding tool or a pair of pliers for the taps as they have no heads on them.
That's really all I can say apart from the pitch markings. You may be at a loss where your pitch is when you get to it, they are marked out with a funny system that's not at all obvious. Somewhere at four points near the pitch edge will be some little red blobs of paint, these denote the perimeter of your pitch and can be a little confusing. Ask another of the brits there if you need it explaining.
Enjoy it and let us know how you get on. But do come back to me if you've any worries at all or questions.
Cheers
Nick