Ask Before You Donate

Do not simply "leave" your unorganized to a library, archives, or other facility without first asking them if they would like to have them; if they have the ability to store, maintain, and preserve them; and if they will allow access to your materials.  That will help you to make a better informed decision.

And, if at all possible, when you are still able you should organize your materials. No library is going to want unorganized, unsourced, photocopies from unknown books.