Something we have discussed previously but there are a lot of new hatchers, so I will post it again.
 
If a chick doesn't hatch on it's own, it can be for a number of reasons.  Some are genetic, some are situational.  Bad position, stuck to the membrane, to weak, too small, died before hatch.   These can happen if parents had poor nutrition, the temp wasn't right, poor handling (big one for shipped eggs) and so many other reasons.  If you decide to help a chick hatch, it could be deformed, not ready, too small, yolk not absorbed, blood not absorbed.  If it is deformed you have to decide is you want to help it or cull it.  If it is too small it may need extra care and need to be seperated.  If the yolk isn't absorbed, it needs more time.  If the blood hasn't been absorbed, it can bleed out.   If the reason is genetic aand you save it, you can be passing on the bad quality if you breed it.  If it is situational, it could heal and thrive to be a great chicken.  The more you help, generally, the more you will have to help.  The chicks will get weaker in time if continuted to breed. 
 
The most difficult for me, is trying to save the weak ones and they die anyway.  I have to say for me, it's more often than not.  Some people on here are great at being able to tell which to help and which not to.  I am not.  I was trying to help most of minebut this time around I am not.  If they are strong and healthy, they will hatch.  (Ok, I may help the one that are just stuck,but that's it). I had too many heart breaks last time.
 
This is just to give you a heads up.  Which ever you choose, there are people on here to help with advice.  I was not prepared for the heart break.  And it is not easy.  You need to keep them damp and warm.  Just be prepared with tissues.