De-greaser/cleaner, Fenwicks FS-1
Dilute 1:1 with water for cleaning the chain and degreasing greasy things.
Dilute 10:1 with water for cleaning the bike.
Instructions:
Spray on, go and put kettle on, while tea is brewing rub well with a washing up brush (not the one from the kitchen, buy 5 for £1 from poundland) making sure to get in between all the sprockets of the cassette and pay special attention to the chain, really go to town on it. Go and drink tea. Hose off. Job done your bike and chain will now be clean!
For chain lube I use Rock n Roll Extreme. Both products available from Wiggle. I bought a 5 litre bottle a year ago, I have used about half of it, it costs but lasts for ever. I clean by work bike, particularly the chain, every week, my other bikes get cleaned after every ride.