Hatching chicks - Choosing the right eggs

I'm very excited as literally, just in the last hour, both sets of eggs have arrived to me, at work!

I bought both off Ebay - maybe this was a foolish thing to do, however the feedback from both chicken breeders looked very impressive and they both made the following points:

1.  All the birds are unrelated
2. The birds are DEFRA registered 
3. The birds are free range
4. The seller stated the eggs had over 90% fertility
5. The seller said they would be posted Special Delivery (which meant they wouldn't go through the normal postal service so the eggs should be better protected)
6. The seller stated that the chickens were de-mited regularly
7. The seller stated that the eggs were fresh and laid within 48 hours of posting

So here we have the Black Orpington eggs and the smaller, Belgian d'uccle eggs! I thought I'd try and hatch both so that when the chickens are a bit larger and integrated into my friends larger flock, the Black Orpingtons could protect the smaller d'uccles, if the other chickens tried to pick on them (as they'll assume they're siblings?) whether this is the case or not, I don't know - either way, my friend is very happy to have some more Orpington chickens as that's what he has at the moment :-)

 As my incubator only has room for 10 eggs, I'm not sure if I'll be able to fit all 12 in - plus, I don't know if this will be to the detriment of the others. Unfortunately my incubator didn't turn up yesterday, therefore I am really hoping it was delivered today!

Whilst this is annoying - I don't actually have to incubate the eggs straight away. In fact, when reading lots of chicken hatching literature, a lot of books and websites state you're supposed to leave the eggs for a minimum of 48 hours (maximum 7 days - after this, the fertility of the eggs decreases rapidly) with the pointy side down and in a cool room.  When you're ready to put them in the incubator, you're supposed to let them gradually warm up to room temperature and then pop them in - Apparently, if you store the eggs the blunt side down, you could actually injure the chicks - Oh! And apparently you're supposed to tilt them 45 degrees and change that tilt twice a day...

I'm learning loads!