Is there any way to give permission to a specific field of a list or library? I want one of my users for example cannot add or edit data in a specific column.
Can I set permissions to the form and its fields??
You cannot do that with the native sharepoint's feature. If you want you can find some feature, in codeplex, like this: http://sptoolbasket.codeplex.com/wikipage?title=SharePoint%20-%20List%20Columns%20Manager
And then make the field read-only :