Parachuting is weather dependant, and unfortunately even in high summer there are occiasions when you may not be able to enjoy your skydive on the day that you have chosen. This will be disappointing and means that you will have to revisit the airfield at a later date to complete your jump. This is a good reason for booking to jump at the closest centre to your home, as you may have to make the trip more than once. If you are organising or are part of a group, then this becomes even more important.
Some centres operate at weekends only and some are even Sundays/Bank Holidays only. If in doubt then ask, otherwise, if you do have to rebook you are automatically limited to returning only on the days that the centre is open. Be aware, unlike your provisional British Skydiving membership which is valid for one year, your initial training/briefing will not be recognised anywhere else until you have gained a basic licence or at very least completed several parachute descents.
If you are intending to take up the sport as a hobby then you not only need to think of your travel to and from the airfield but also whether or not the parachute centre is actually geared up and keen to progress student parachutists through the system to gain experience and certification.
Finally, are you dealing with an 'agent' or an 'outside operator', or with the parachute centre direct? Booking direct does have advantages and few, if any, disadvantages. Booking direct will certainly save you money!