Clearing Your Schedule
Baby chicks require constant care and monitoring, so make sure your schedule is pretty clear for the first 4 weeks! Don't plan on vacations or even day trips unless you have a baby chick pro on standby. Make sure you or a member of your family are available to check on them at least five times a day.
Deciding Where They're Going to Live
You can keep young chicks almost anywhere: their small size makes them easy to handle! They grow quickly, though, and by the time they're three or four weeks old they'll be taking up a lot of space and making a big mess, so preparing a living space for them is actually quite important. (The good news is that you can transfer them to their outside coop at 4-5 weeks of age, so you won't have to deal with the mess for too long... More on that below.)
Ideally you'll have a garage, workshop, basement or another predator-proof and draft-proof environment that's not in your main living space. Why not the main living space? Baby chicks, just like grown chickens, love to "scratch" their bedding materials, which creates a very fine dust that gets everywhere. The older they get, the more dust they make. Baby chicks also have a smell... It's not decidedly bad, nor do we find it overwhelming, but you may not want it in your house.
If you don't have a garage, workshop or basement in which to keep them, pick the next best option. Do you have a three season porch where it won't get too cold? A spare bedroom whose surfaces you can cover? If none of the above, does your kitchen have an eat-in area not too close to prep surfaces that you're willing to sacrifice for a few weeks? Choose the best possible option keeping in mind that wherever you keep them, they must be safe from predators and drafts.
Creating a Suitable Living Environment
This is the one of the most important part of raising happy, healthy chicks.
The baby chick house (also known as the "brooder")
Baby chicks need to be protected from drafts but still have adequate ventilation. This can be in the form of a cardboard box with holes for ventilation, a large plastic storage bin, an unused bathtub, or even a kiddie pool! All of the above have been used with success.
Whatever housing solution you go with, make sure it provides 2 square feet per chick. It sounds like an awful lot, but as they get older (and bigger) you'll realize why this is necessary.
A heat source
Baby chicks need to be kept pretty hot. Think sauna! The first week of their lives they require an air temperature of 95 degrees, the second week 90 degrees, and so on - going down by around 5 degrees per week until they're ready to transition to "outside".
When you chicks are fully feathered out. They can be outside at all times.