If these are your first chickens, chicks ever... Buy the book "Raising Chickens for Dummies".. great book, good info. on all subjects -- as well as use the Search here on BYC for all subjects. And, is hubby planning on building a coop and run for them? Or, do you already have other chickens and a coop, run, etc.? There is a book, I have not read.. "Chicken Coops, or Building Coops for Dummies" as well, for ideas and plans, I think?
Mine didn't smell much... I know that newspaper alone can be too slippery for the little chicks feet/legs.. so.. I layered MANY layers of newspaper first.. then, put some hay (I used alfalfa hay) on top of it, leaving a space for the food and water.. and, then, I would go in daily, pull up a couple layers of the paper, hay, mess and all.. (moved the chicks into a pet carrier first)... put some fresh hay, clean water and food.. (water and food changed as often as needed or twice a day).
There was little smell -- but, I didn't have 15 chicks and as they get bigger it will be worse, I am sure.
If you can afford to buy a pre-built coop (and run), that would be good... if you can't afford that.. a brooder in the garage?
I don't think a metal shed is the best idea... unless it's clean, empty, has a window or two with screen (ventilation), closes all the way (predator proof), and has electricity, is safe. And, even then, a brooder would still be good centered inside it, in my opinion.
You have less than four weeks to go... until they are "feathered out".
Best of luck.. they will be worth the trouble now.