Humidity is extremely important especially at hatch time. Opinions differ on days 1-17 about humidity, some people (myself included now) have gone with a "dry incubation" method in which the first 17 days you don't (unless you are in a very dry area that humidity is naturally less than 20%) add water and just keep an eye on the air cell (or egg weight if you choose that method) to make sure that you are loosing enough moisture from the egg, but not TOO much. On day 18, when you stop turning the eggs and you go into lockdown you need to make sure the humidity is upped to 65% +. You use a hygrometer (you can buy online or in stores) to messure the % of humidity. If you do not have enough humidity during the process the chick can become shrink wrapped and die if you have too much humidty the egg doesn't loose enough moisture and they can drown. So, yes, humidity is important. (The non dry method for days 1-17 most try to keep it between 40-55 I believe.)
This time at lockdown I filled my water wells and I added wet sponges to my bator with the eggs. This worked well for me and it was much easier to slide out the sponge, wet it and slide it back in without compromising humidity during lockdown.
Good luck on your future hatching.