Here is some straightforward guidance to help you have an enjoyable Firework display.

Set up a committee.  One person should be in
    charge of safety arrangements.
Make sure you have adequate insurance to
   cover personal injury and damage.
Give details of the event to the Fire and Rescue
   Service.

Choose a clear, well-mown space not less
    than 18 metres (60 feet) from buildings, trees,
    wooden fences, overhead cables, car parking
    areas or other firework display.  Where there
    is less space, such as in a pub garden, the  
    organiser should consult the Fire Authority. 
    Allow at least 50m x 20m for your firing area
    and a dropping zone for spent fireworks of
    100m x 25m back on the opposite side if the
    dropping zone.

The site needs a suitable entrance for
    emergency vehicles.  All entrances should be
    well lit and wide enough for spectators.  You
    should also cater for disabled spectators.
Car parking should be well away from the
   display.  Signpost the car park clearly and do
   not permit parking elsewhere.
You need to make safe any nearby
   combustible materials such as stacks of
   timber, hay and straw.  The direction of the
   wind is important as the bonfire must not blow
   towards spectators or combustible materials.

Water fire extinguisher.
A hose (if mains water supply is available.
Buckets of water or sand.
Fire beaters.
Fire blanket.

The usual ratio is one steward to every 250 people present, but more stewards may be needed to cover each entrance and exit.  They may need special training, such as using the fire-fighting equipment.  They should also do the following:

Act as car park attendant
Provide information
Monitor the bonfire area.
Keep spectators behind barriers.
Ensure that nothing is thrown onto the bonfire
   and that it does not spread.
Manage the public (Particularly if alcohol is
   allowed).
Call and liaise with the emergency services.
Collect rubbish
Clear up
Check that the bonfire is extinguished.

Stewards should be over 18 years of age.  Fluorescent jackets make them easily identified. They should know who is in charge of the event and have a means of contacting them, such as a two-way radio.  They should be aware of the telephones.  They remain until the event is over and ensure that the site is safe.  Committee members and stewards should all have torches, so check that you have plenty of batteries.  Use prearranged coded signals, audible throughout the site, to warn the stewards when an emergency has developed.

You can seek advice from the police about
    over-crowding.  Make sure your stewards know
    what to do in an emergency and that they have
    practised safety drills.
Spectators must not enter the display area. 
    Put up clear signs and stop the display if
    anyone does come inside the area.
Spectators should be able to move away freely
    from smoke, sparks and heat without being
    trapped by the crowd.
Fireworks and alcohol do not mix.  None of the
    organisers should have alcoholic drinks.
Do not allow spectators to bring their own
   fireworks, even sparklers.  Have signs
   explaining this at the entrances.