This sounds a bit rude but don't get too friendly, because if there are problems it can make it difficult to criticise. I don't mean ignore them and not make tea etc, just don't try and make them your best mates. Our "head" builder asked us only to offer coffee once in morning, and after lunch, (and not too hot so they didn't take too long drinking it - his suggestion!).
You will find you can't wait for them to start, and about halfway though can't wait for them to finish. It is really stressful (we had walls being knocked down when my mother was taken ill, and I nearly lost the plot with them leaving the radio and lights on in the house then going out for an hours break, poor chaps). I also had a fit when I came in and found them laying raw slate floor slabs up against a newly painted wall in a different room - it just didn't occur to them it might be a problem!
Don't be surprised if you end up in tears on more than one occasion, or if you feel like tearing their heads off - our builders really weren't very house trained and didn't understand that whilst they could walk away from the mess at the end of the day, we couldn't. If that sort of thing bothers you, make it plain right at the beginning (politely) what you expect of them. Aggro comes with misunderstanding, they don't do it deliberately to wind you up.
Having said all that depressing stuff, it is so exciting - I used to run around seeing what they'd done after they'd gone home, and jumping up and down with excitement! It will look as though nothing much is happening for ages, then suddenly it will all be done.
Be prepared for lots of decisions quite early on - probably before you're ready to make them. We had to make decisions about window styles, lighting, heating etc whilst the conversion was still a shell, and I was really caught out! The internet is a wonderful research tool though, we did a lot on-line, then haggled with local suppliers on price - mean, but useful.
Good luck - how about some before, during and after piccies!
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