General Advice is available from various sources on the Internet, the following is a good source of advice for riders of all abilities
The main London Cyclists advice is available at http://lcc.org.uk/pages/advice
Why Cycle is a good site for impartial advice at http://www.whycycle.co.uk/
For road cycling go to http://www.road-bike.co.uk/
For general advice on all things cycling then go to British Cycling
Here is a link to some great biking tips all the way from Portland, Oregon, USA.
Here is a useful beginners’ guide.