People will love saving things for you to use in your classroom – egg cartons, old ribbon, film canisters, plastic whatevers. In fact, so much will be collected, you will never ever be able to use it all.
So don’t keep it all. I say this because if you keep it all, you will not be able to store it well, and the mess will make you crazy. (Or your co-workers crazy.) However, always graciously accept anything given to you. If you refuse something, you might miss out when they have something really cool to give away!
Recycle un-needed donations if it makes you feel guilty to throw things away, but please don’t keep a lot of stuff out of guilt. That’s poor stewardship.
It reminds me of a little saying – “When life gives you lemons, thank life politely and then throw them away when life isn’t looking.”