The following websites might already have been mentioned on other websites, but I thought it might be helpful to have a dedicated site for them as well:

• gov.uk – The website of the UK government contains lots and lots of helpful information about renting, recycling, driving, public transport, benefits, living in the UK, working, visas …
• shelter.org.uk – Renting Information, Help and Advice
• tfl.gov.uk – Transport for London
• oyster.tfl.gov.uk – oyster card (Public transport)
• nationalrail.co.uk – public transport information, especially train
• railcard.co.uk – benefits when travelling by train
• gumtree.com – buy and sell all kinds of things

For websites for finding a new home/house share/ flat, please see Renting in the UK.

Information provided by your borough (german: “Stadtbezirk”)

Some things might depend on where you live, such as recycling or the council tax valuation bands. Helpful information can be found at the website of your borough which is something like: {name of the borough}.gov.uk (for example: bromley.gov.uk) or {first letters of the name of the borough}.gov.uk (for example rbkc.gov.uk for Royal Borough of Kensington and Chelsea). If you are unsure just search in the internet for “{name of the borough} gov.uk”.