Administering SharePoint mainly consists of setting it up, which is much easier than you expect, adding the content, which can be just dragging and dropping in whole directory structures and files, and then organizing the files better by giving them categories or other metadata. This is done either through the Web interface or through the SharePoint Client: a program what means you can access SharePoint as a Web folder and then right-click files to select options like "edit profile". Or add files by dragging them in individually or in bulk.

Setting the security is also important, using NT accounts, either NT4 or Active Directory (or both in mixed mode) you can give users access to files/folders the same way as you do in standard Windows. Users can be grouped and the groups given access privileges to help manage this better. Also SharePoint has 3 Roles that a User or Group can be given on a particular item. Readers can see the item (i.e. document/file or folder) but not change it, Authors can see and edit items and coordinators can set security privileges for the part of the system they have control over. Thus, you could set 12 different coordinators for 12 different folder trees, and they could manage who can do what within that area only.