I haven't been through planning permission issues, but some preliminary things for you to consider occur to me, such as:
What's the size of the land?
What is its current planning permission category?
How overlooked (shaded) is the site?
Are you thinking of letting plots to others, or just to use it yourself?
Does it have a water supply to it?
Does it have parking on site?
What is on the current land - is it long term grasses (for example), or has it had building and/or hardstanding on it? Could it be contaminated from previous use?
What timescale were you thinking of using the land for? Do you have an end date in mind?
The
NSALG has a leaflet you might find helpful.