What Does It Cost?
As with all things, prices will vary across the country according to area and the facilities offered. To give you a guide, the schools I've visited in the area south of Birmingham charge;
1 hour private lesson
Group lessons usually have a maximum of 8 riders though this number will vary according to the size of the schooling arenas.
Price is no indicator of quality. I've found much better instruction at a smaller, cheaper school than one which thought a lot of itself and charged accordingly.
If you can afford it, have as many private lessons as you can in your first few months of learning to ride. You'll probably find that a half hour lesson will be quite long enough until your muscles develop. Being able to concentrate intensively on the early essentials like position and balance, on a one-to-one basis, will pay off later.
After a while, group lessons can be a lot of fun especially if there is a regular gang of people to swap stories with each week. Group lessons taken too early on can be off-putting as it's easy to lose confidence by going into comparison with the other riders (if they happen to be more advanced than yourself).
During the lesson you have other riders to think about and try to miss! You also learn by watching your compatriots get things right and from their mistakes. However individual time spent with each person by the instructor is obviously much less than with a private lesson.
Next - some essential safety items.