Forest Research, (the research agency of the Forestry Commission) have produced an Urban Tree Manual, advising on what to do about planting trees in towns and cities. It contains a number of useful links. You can download it by clicking > FRUTM 

There is a brief synopsis below:

Location:
* Site -choosing the site and assessing the constraints.
* Soil – the type of soil determines what will thrive – what is growing well locally?

Tree Selection:
* Wich trees are suitable – they may grow to be tall
* Ecosystem support for wildlife
* Negative effects of some trees
* Resilience to Climate Change

The benefits of trees:
* Air quality
* Shading and Cooling
* Improve mental health
* lower unban heat-island effect by 3-7 deg C
* traffic calming

Biodiversity:
* Improving biodiversity and avoiding monoculture

Procurement:
* Adoption of a policy
* Should residents be involved in tree growing

Planting:
* Ground preparation
* Planting in containers

Pests and diseases:

Tree retention and removal: