The London Plan is the Mayor of London’s over-arching strategic planning policy and covers all Inner and Outer London boroughs. Each borough’s local planning policy must conform with it. The Mayor makes other strategies too. [this page needs revision]
From one page on the GLA web site https://www.london.gov.uk/what-we-do/planning/london-plan you can find your way to most of the relevant GLA documents.
Following substantial revisions, a new version of the Plan appeared in 2011. Through 2014 there were consultations on Further Alterations (FALP), details of which are here (with a separate menu to help navigation) and a new Plan incorporating the revisions came into force in March 2015.
During 2015 the Mayor published a new set of Minor Alterations (MALP) covering the relaxation of upper limits on car parking in new housing schemes in the outer suburbs and some changes to housing standards. Just Space made objections and there was an Examination in Public (hearings) on 21-23 October. Details of the process are here.
 A completely new London Plan is being prepared in 2017 (under a new Mayor and Assembly elected in 2016) and Just Space is busy supporting community organisations to contribute to setting the agenda and contributing positively to the plan – in contrast to earlier years where citizens could only comment on a draft made by the Mayor. Details of all these Just Space activities, and how to join in, are here.
Many other planning activities go on at City Hall or in linked organisations like TfL and the London Enterprise Partnership but none of these is subject to the full statutory consultation and EiP process which governs the London Plan so their democratic legitimacy is much weaker. Important among these other plans are
The London Infrastructure Plan 2050 A very unofficial document but the site of major decisions on the future of the city, never debated in public.
The London Economic Strategy was not updated for many years. However in January 2015 London First, a business lobby group, submitted a report London 2036, largely prepared by consultants McKinsey and Co, to the London Enterprise Panel. This activity is in some way a precursor to the production of a new London Economic Strategy.
Just Space work on the London Plan up to and including the version published finally in 2011 is, for the moment, all on the web site justspace2010
The debates about the last lot of Amendments to the London Plan in 2012/3 (known as REMA) were covered in our wikispaces site [now non-existent and probably lost forever ]