Most of it follows NCRs (National Cycle Routes). These have most turnings indicated with helpful blue signs.
Handy maps are available from Sustrans website although they are quite expensive and occasionally frustrating unclear, but they help to support a good charity.
I’m hoping to develop a similar system to Camden Cycling Campaign to provide more routes, details and enable collaboration with other cyclists. If you have any programming knowledge or simply knowledge of good routes feel free to contract me, any help would be appreciated.
Hope it helps if you’re planning a ride in the sun!