I am facing problem in giving a visitor user permission as "Contribute" on a particular folder inside a document library. In my scenario the user is added in the top site collection inside the visitor group to have read access to all the sub sites, but for one sub site's document library I have a sub folder on which I want to give the user contribute access. I went to that particular library and then that folder selected manage permission and then given the user permission as contribute (by breaking inheritance of permission). Now when I login with the users credential on the document library folder I cannot see the "Add New Item" link, whereas I can edit and delete the previously added files. Can anyone help me in this? What step am I missing?
Since you are using Sharepoint 2010, navigate to teh library, open library permissions and click "Check permissions" for that user. That should confirm they have contribute access.
If they still cannot add a document, check the contribute permission level has not been customised (eg removed the Add level).
Give the user higher permissions. Try "DESIGN" or higher. Since you are breaking inheritance, this user will only have access to this particular library.
If you don't feel comfortable granting higher permissions. The users should still be able to add new documents by navigating to the ribbon and trying to add a document from there.