How to

The International Space Station (ISS) circles the Earth every 90 minutes. Depending on the orientation of the station's solar panels and the Sun, you may be able to see the space station cross part of the sky, sometimes emerging from - or vanishing into - the Earth's shadow. It can become quite bright, brighter than any star you will see in the sky, but it helps knowing when and where to look for it. These services are very useful:

NASA's Spot The Station is a site with timings and rough indications of where to look, and you can sign up to alerts.

Heavens Above has a lot of useful information; first enter your location in the top right (it will remember it next time), then check the link "ISS" under "Satellites" for a list of predicted transits. For each of them, clicking on the date will pop up a chart of the skies above you. Familiarise yourself with the constellations and directions a little while before the transit so you know where to look and won't miss it.

A note on brightness expressed in magnitudes: this is an ancient, rather awkward system which however mimics the human eye's response. A small, or more negative, number means brighter. The brightest stars in the sky are about zero or minus one; the faintest are around magnitude four to six depending on the amount of light from streets and buildings and moonlight.

Good hunting!