Hi,
The nearest Parachute drop zone to Manchester is the Black Knights Parachute Centre, Cockerham, Lancs. This is where I jump so I can't claim this is an unbiased recommendation but I do feel they are very good with 1st time jump students.
Their web site is
http://www.bkpc.co.uk
I Hope that helps, if you'd like any more info feel free to send me a PM.
Regards,
FreeFallFun