advice for making a hotbed

I want to build a hotbed (finally), I want to use it for starting my tomatoes early and for rooting cuttings. I want to build it on the ground and "dig" it in with tree mulch. I use an old window for the top.
Now my questions:
1. Is it OK to pick up horse mannure on a paddock or would it not heat up properly because the manure is already there for some time?
2. I read in one description that I need to make a heap of manure and leave it there for about ten days and turn it over several times - wouldn't I lose too much "heat" like that??
3. Do I have to vover the window over night?
4. What temperature do I get inside - say outside it is still freezing over night and I have my seedlings in there - what's the approx. temp. difference?
5. There are different opinions on how deep the manure should be 30- 60 cm?? It probably depends on how long you want to use it?
6. They say that you use manure and straw - I happen to have manure and woodchips would that work too?

Gardeners world (BBC) etc...  have at least one episode dedicated to your question. Sorry to say, it does not run on my machine - perhaps it does on yours.  

http://www.bbc.co.uk/programmes/p00r9xf5

http://www.bbc.co.uk/programmes/p01xrn7y

I found this
book, written by Caleb Warnock. He goes in to great detail about hot beds. My hubby and I tried this one winter, it didn't work for us, but I'm fairly certain that it was because we weren't using fresh manure. He got a couple wheelbarrow loads from a friend, and while it wasn't composted, it certainly wasn't super fresh. It was probably a month or two old. We are going to give it a try again this winter.

HOw cold is your winter?

It gets fairly cold; nightime lows are usually in the teens (farenheit). Daytime highs around 30 degrees. But we usually get a good amount of snow that helps to insulate things...

So your climate is colder we get around 20F (-5C) at night in winter. The question is how much manure and how fres does it have to be? I want early tomatoes!!

I can't remember how much manure was suggested. .. I'll find that book tomorrow and see what it recommends.

Okay, found the book. He says that he uses about two 5 gallon buckets of manure (no older than one month). This fills a 3x2 foot hotbed.

He digs the hole roughly 16 inches deep, and puts the manure about 12 inches high. The top four inches are for the soil and compost.

Angelika the horse manure needs to be as fresh as possible, say max. 2-3 weeks and better of less than one week. If you can find enough, simply make a large heap and add some 'bedding' of straw, hay etc. Woodshavings is possible too, but they take some notrogen from the manure so be careful if growing above the heap. Don't turn it! Use straightaway.
I use hotbeds for propagation in a greenhouse, but outdoors I find the heat is often blown away as much as used by plants. We explain it in our new book, which is in a thread here.

Thanks I found the turning strange anyway. I won't grow into the manure straight away but in pots I probably will strik cuttings there too and I do that in sand anyway. I will have to cut some old roofing sheets lenghtwise for the bed surroundings but I will heap everything in so that the glass is level with the surrounding mulch.

Find and read "The Humanure Handbook". When we have been composting humanure we have had effortless hot compost heaps, every time. When we only compost garden waste and kitchen scraps we rarely get the heat as high.