I've heard different stories about the humidity.  Basically I read to keep it around 50% then raise it at the end to 70%.  But I discovered I have a higher death rate that way.  They where dying just before pipping.  When I opened up the eggs there was a dead chick with the yolk absorbed.  So I figured they drowned.  So I lowered it to  between 50 and 60% and the chicks come out sticky and I have to fluff them up after they dry myself or wait several days for them to rub themselves fluffy.  I actually had most of a hatch fluff up when they dried and wasn't sticky when they hatched with the humidity around 45%.  So, what ever works for you I would say.  I don't mind fluffin them up myself, but they do.  I don't leave them in the bator either.  When they dry, they come out unless they are weak.  I take them out and fluff them if needed and they go in the brooder.  I don't like my bator to get all pooped in.