They will nest right next to each other. They usually find a favorite spot. Either on the left or right hand side of the nest and that is where they will lay from then on. They usually lay their eggs at different times of day so its not like all 10 hens will be there at once. If its just 2 or 3 they will just slide in next to each other.
As far as heat they say 95 for week 1, 90 for week 2 and so on. Minus 5 degrees each week. I dont monitor the temp. Just watch your chicks. If they are huddled under the lamp they are to cold. If they form a ring around the outside of the lamp they are to hot. You want them to just move freely around under the lamp. Start your heat lamp out low and just slowly start raising it higher and higher until around week 5 or 6 or until the outside temp stays warm. You will notice when their wings start forming and they start jumping and hopping around the heat lamp becomes less important.
They also claim feed them "Sugar Water" for the first week. I dont know why but we did it. I have no idea the mixture.
Are you getting these from 4-H or Tractor Supply. Both places will have leaflets that will fill you in on what small stuff you need to do.