The space agency has set up a special website inviting you to register to receive alerts informing you when the ISS is passing over your home. You simply input your geographical location, tell NASA if you want morning or evening alerts (or both), stick your email address in and wait.
You might receive an alert to your inbox the next day. Or you might have to wait a month or more. There's really no way of knowing when the station will be next passing overhead until you get that email.
I received my first alert about two weeks after registering. The information in the email, which arrived in the morning, said the ISS would be passing overhead in the evening and be visible for a period of three minutes. It also told me precisely where in the sky it would appear and disappear.
There were no clouds in the sky that evening, so a couple of minutes before the designated time I popped my head out of the window, for some reason not really expecting to see it appear. However, with the kind of punctuality Transport for London can only dream about, the ISS arrived on the horizon exactly on time. The bright white light moved steadily and silently across the night sky before disappearing from view three minutes later.
The ISS serves as a space-based research laboratory and has been orbiting Earth 200 miles up since its launch back in 1998. It's been continuously occupied for over 12 years, and can accommodate up to six crew members. And at 72-metres long and 108-metres across, you don't even need binoculars to see it in the sky.