(CNN) -- CNN is covering preparations up and down the eastern seaboard as Hurricane Sandy threatens to bring "superstorm" conditions.
Here are five things to know:
When's it going to hit?
Sandy's center is expected to be near the coast Monday night, the National Hurricane Center said. It may strengthen a bit before weakening as it moves over land.
Who's in danger?
Millions of people live in areas that could see flooding, the National Hurricane Center says.
From South Carolina all the way up to Maine, people are being warned to prepare -- and, in some cases, evacuate.
See details here.
How should people prepare?
Shuttering or boarding windows and doors and bringing items in from the outside are only the beginning.
You should also prepare your refrigerator, fill a bathtub with water, make sure your car's tank is full of gas, and take other critical steps.
CNN provides a list here.
What is my state doing?
State and local officials are announcing new steps by the hour.
CNN is keeping a running list here.
What about transportation?
Subways, buses, trains and more are being shut down in various places as the storm approaches.