For one of the US Apprentice series a contestant did a blog published the day after the show aired. He gave away quite a few interesting tid-bits about the workings of the show.
One of the things he said was that they get a long list of rules at the start of each task stating what they can and can't do, things they must include. I get the feeling on the first task one of the rules was they must do a hot food option and a fresh fruit option.
Each team has 2 camera crews and 2 producers with them, so they can only split into 2 teams. In that team there has to be 2 people, even if it only needs 1 person to do what they need to do. One person wouldnt be allowed to nip up the road to make some photocopies on his own, for example.
He gave away a host of other things you just don't think about such as getting out of the car. They get out of the car each time and are filmed from inside, the crew get out and the candidates get back in and shut the door so they can then be filmed again getting out from the out side.
Any premisis they want to enter, the producer has to go in first to ask permission from the owner.
The 2 biggest surprises were that the show is filmed on a 3 day rota, not a week like I assumed. Day 1 they get the task and plan things out. Day 2 they carry out the task and go to the boardroom in the evening. Day 3 the winners have their reward and the losers have extensive interviews to camera which we see throughout the program. The fired candidate comes back for their stuff whilst everyone is out. The next day they start all over again. Now that was on the US show, I dunno if that's the case here, but I don't see why not. It doesn't make much sense to have them work 2 days and then have 5 days off when you are employing 4 camera crews and everything that goes with it.
The other surprise was that the loosing candidates don't go home, they go to a hotel where they all stay until filming of the series is finished. He did give a reasoning behind that but I can't recall what it was.