The idea is simple: pick one of over 11,500 bikes from one of over 750 docking stations dotted around the capital. Cycle. Then drop the bike off at another docking station. The access fee is £2 for 24 hours. All you need is a credit or debit card. The first 30 minutes are free; it's then £2 for any additional 30-minute period.
You can take as many bikes as you like during your access period (24 hours), leaving five minutes between each trip. Find a docking station using the website, or download the useful app.