Hi Alex,
Another option is a course "Sitewide Resources," in which you enroll all teachers with a student role and allow guest access so that students can download material, but not add material.
Then, you add a database activity (see attachment). A teacher can add the resource or tutorial in this database and link to it in his/her course. A teacher can edit what he/she has added in this database activity, but not other resources. One advantage of this approach is that the site admin has not all the work (like in adding a main block to the front page). You can also add a link to these resources in your Custom menu. If you want to hinder instructors to delete their uploaded resources, I guess you can do this within the database activity, but I haven't tried it.
With kind regards,
Hartmut