I've also ordered the routemaster, as this will be my first foray into the world of buses, as I usually build cars. Are there any books or websites that you would recommend regarding adding detail etc.

http://www.flickr.com/groups/1893666@N22/
is a Flickr group with photos of several different Revell models that have been / or are being built - some very good indeed.
There are also extra adverts and blinds that can be downloaded and printed including adverts for the interior.

Capital Transport
http://www.capitaltransport.com/
publish a lerge number of bus books, including several on the Routemaster.
The best would probably be Routemaster Vol 1 by Ken Blacker, but it appears to be no longer listed - Amazon list it -
http://www.amazon.co.uk/Routemaster-...9&sr=8-1-fkmr1
This gives the early history of the Routemaster, Vol2 still available from Capital would deal with the more recent history (1970- 2000)

I bought the Haynes Manual which has quite a lot of photos of the oily bits. Amazon do this for around £15. There is a minor issue with the AEC engine in that one part on top of the engine (breather pipe or whatever) is not correct where it attaches on the offside of the engine. As this is next to the driver it is fairly well hidden. I have a couple of very good photos of what this should be like that I was able to get from a Routemaster Group on Facebook.

A Google search will pick up a pretty good selection of photos for reference.

There have been a build or two on the Britmodeller site which may also be of help. I am a member there (I used the name Mxyzptlk there).