SharePoint site visitors cannot access or edit files in site shared library

[Rexter]

I have to give all members of my SharePoint site edit permission in order to for them to have access and edit files and documents in the sites shared documents library. This means any member can edit the actual SharePoint site itself, which is far from a best practice. I think the workaround is to create a separate SharePoint library and then link it to my site, so visitors cannot edit it but have access to and edit documents in another site. Is this a good workaround or does anyone have a better idea to address this issue?

[#2]

You just need to create a document library on the site and break permissions. And allow all visitors Contribute access on the document library. This way all visitors can add/edit documents within the document library only.
You can also restrict Deletion for documents but creating a separate permission rule which can allow Add/edit documents but do not allow delete.

[#3]

Hi, I have been tasked with redesigning an existing SharePoint site with an existing library that I am now an owner of. Unfortunately, the option to break permissions tool or to create separate permissions has been deprecated by Microsoft. Once a library is created, its permissions at the time of creation are locked now in. That said, what I really need is a good, scalable web driven document management system that can easily be modified that doesn't require heavy IT support. (I am not an IT person). Any recommendations?