The book The Richest Man in Babylon was mentioned by a speaker at the Wandsworth Property Group. I have never read it but understand that due to the writing style it takes a little while to get into. However
I recently attended the Wandsworth property meet http://www.meetup.com/The-London-Wandsworth-Property-Group/events/17334928/ run by Brendan Quinn and his assistant Katalin Toth of KatPR. Although quite an intimate event it is very informative with lots of top speakers.
Including a solicitor giving guidelines on lease extensions. Rating 8/10