What to do with old apple products

In our home we have a basket full of old Apple products, some of which are in relatively good condition (a couple of iPhone 5s, A couple of iPhone 4 and 4s’ and many old iPods). I am struggling to get access to these devices as I want to wipe them clean and sell them. Who or where is the best place to go to for a reasonable price to wipe and restore these devices for me so I can go on and sell them? Our oldest device is one of the original ipod Nanos and the original 30GB ipod. Thanks in advance.