Our golden wyandotte went broody. After looking up ways to "break" her of it,a friend convinced me to try and just go with it. Since we don't have a rooster we found someone who has fertilized eggs and made a trade. We put 11 fertilized eggs under her today and she seems like the happiest hen on the planet. Here's the thing, we've NEVER done this and have no idea what to expect. She's taken over one of the regular nesting boxes in the coop. We built an additional one for the other ladies so they leave her alone. I read that we should check the eggs at 10 days for viability and that they should begin hatching at day 21. What else should I know?
We have an area where we've raised chicks with a heat lamp before, but never with a mama. Should we separate them at "birth" and put them under the lamp? I'm concerned about what the other hens may do if they're all together.
Well, the good news is that you have about 20 days to decide how you want to handle your broody, the bad news is that there are as many opinions out there as there are chicken people.... If you go back about 100 pages on this thread and start reading you will find many different situations and how folks handled them.
In my coop the hens are able to hatch and raise their little ones with very little human intervention, except I do give some of the new or timid broodies a few days of peace and quiet by sectioning off their nest area until the chicks are a few days old. Other folks have their hens and chicks in a totally separate pen area and there are many options between the two extremes.
Most folks find it easiest to allow the hen to raise the chicks with little assistance. If the hen has a safe and draft free nesting area and a good source of food then very little else is needed for her to raise her brood. Unless the hen shows she is incapable of raising chicks (there are rare hens who fail miserably at motherhood, even if the do the setting and hatching well) .... if a hen proves to be incapable or homicidal even then the chicks may need removed for their safety.
The only time I have ever used a heat lamp was to keep a broodies water from freezing when we had January hatches... and the lamp was only over the area of the water, not the broodies nest. A mama hen is able to provide plenty of warmth for her chicks as long as she wasn't given too many eggs/chicks, she should be able to easily cover all of her chicks for at least the first 3 weeks in chilly weather, if she was given too many eggs or chicks then she may need supplemental heat near the nest for chicks who don't fit under her.
If concerned about others in the flock (understandable if the flock has no chick experience) then the best answer is to probably provide a fence around the broody nest the day of hatch and for a couple of days after.... this will allow the hen to teach the little ones to recognize and listen to her vocal commands and you will be able to evaluate how the other flock members behave around them with the safety of the fence. Allow (out of fence) interactions only with supervision until you are comfortable that the flock isn't nasty to the little ones and then decide from your observations whether you want to leave the broody and chicks in with the rest of the flock or provide them separate quarters.
Good luck with the hatch and be sure to check back in with pictures!
I was mad at my hen for sneaking eggs away, as we don't need more chickens, but I decided there is nothing I can do anyways, so I may as well be excited about the adorable chicks! 
