I recently acquired and start using Office365 and would want to use SharePoint as our document management system but need to know where to start. We have thousands of documents that I want to index and make available to various departments with different access privileges. Where can I start?
For your "thousands of documents" can you explain a bit more about what types of documents... for example:
Is this typical "file share" content (ad-hoc sets of folders and sub-folders with content created by users)?
If it is in folders on a file share, is their a consistent structure?
Or are you migrating from another ECM system?
How many different types of documents (e.g. invoices, personnel records, marketing data sheets)?
Do you have metadata planned for each document type?
Have you planned out sites for each of your departments?
Anyway, the new "modern" SharePoint experiences for document libraries has rich metadata filtering, document previews and other typical document management features. You can start with modern team sites for this or a classic document center. If dealing with a few 1000 documents total, the modern team sites should be fine. If dealing with 100's of thousands or millions of documents then a classic Document Center would be much better.
There is way more to cover than this, but hopefully its enough to get you started.
You will want to Plan for Search, by this I mean, thinking about how people will want to search for files and then doing a little bit of extra work to ensure that they have an awesome experience when the do search for a file.