The route is filled with pleasent riverside views and various pretty public houses on the river. Good cycle route signs on route 1, although route 4 are a few diversions and poor signage. Best advice is to stick as close to the river as possible and divert on to the roads for a short while. You will see the heart of the gravel crushing industry on route and smells of beer in production.
Landmarks/Pubs for lunch/Sites to see?
Great pubs on route if you stick to the river you really can't miss them. Yhe Trafalgar is located in Greenwich and The Angel is on route 4 near Tower Bridge. Old Salt Quay is also on route 4 between Greenwhich (Route 1) and Tower Bridge.
O2 is on route at east Greenwhich and The Thames Barrier is also on route 1 in East Greenwhich. I found a great City Farm on route 4 just beyond Greenwich called "Surry Docks Farm" which is about 1 mile from Tower Bridge. King Edward III Manor House runis is also on route 4 just outside the Angel Public House and 1/2 mile from Tower Bridge.
Then of course you have Tower Bridge and the City. Total route was around 13 miles.