This is the site which gave us the original inspiration for our trip: http://www.seat61.com/ it is run by Mark Smith and he seems to know pretty much everything you would ever need to know about overland travel. It has loads of hints and tips as well as lots of pictures. Great site, we wouldn’t be doing this the way we are without it.
These two people cycled back from New Zealand to the UK, I thoroughly enjoyed reading their blog: http://www.tandemturners.com/
I’m sure as time goes by I will others to add to the list.