Off heat means they are old enough to be fully feathered and not need a heat lamp. Typically that is somewhere around 8 wks of age, although if it was really cool at night, I'd still give them a heat lamp at night until 10-12 weeks.
As far as day olds - my first ever chickens were day olds. It's not a big deal to raise them from day olds. You just need a brooder of some kind (a plastic storage tote works well, with the lid modified to have a large opening of chicken wire or hardware cloth), a heat lamp (
walmart), and clean water and chick starter feed. Use PINE shavings for litter - NOT cedar. The first week I cover the pine shavings with a layer of paper towels to help them keep their footing.
The first week, the temps should be 90-95. Position the light at one end of the brooder so the chicks can get away from the heat if they get too hot. Then raise the light to make the temp drop 5 degrees each week until they are 5-6 weeks old. Or you can alter the temps by switching to a lower wattage light bulb.
If you click on the 'information center' at the top there is good information about raising chicks of any age. Theres also a great booklet you can print off at
www.mypetchicken.com
Whatever you decide to do, have fun with them!! Chickens are the best!
