If you can still find any quinces grab them, because I have just discovered the best and easiest preparation method that does not result in sore wrists and blunt knives. In the past I have even tried kneeling on a chair to get more leverage as I tried to hack into these notoriously tough fruits!
So......all you have to do is cut them into quarters, cover with water and cook until soft. That's right! No need to peel that tricky skin, no need to lose fingers trying to get the core out! When the fruits have cooked down to a soft consistency they turn pink, and the cores can be simply scooped out with a spoon. The quartered pieces can now be sliced with no need to remove the peel.
Quinces are high in dietary fibre which is useful for digestive regularity, lowering cholesterol and staying full for longer. Leaving the peel on also means that quercetin, (a phenolic compound useful for reducing the onset of hay fever symptoms) is maintained and easily consumed. Although Quince is reputed to be high in vitamin C, the nutritional profiles are based on the raw fruit, so I wouldn't rely on quinces for your vitamin C intake - actually I wouldn't rely on any 1 food as variety is the cornerstone of good health. Eating a rainbow a day is an excellent goal!
Reserve the cores to combine with sliced fresh ginger and water to make an incredibly nourishing and soothing tea for sore throats. The seeds are high in pectin and when cooked will create a mucilaginous (thickened) consistency that is excellent for the irritated and sensitive mucosal surfaces of the upper respiratory tract.