Documents can be added as an attached file in an activity note eg Minutes of a meeting. Activities can be added to contacts and to opportunities.
Search for your contact and click on activity to add a document.
Search for the opportunity for your contact and click on activity to add a document.
Enter the details for the activity and select attach a file.
Additional documents can be added to the company details. These documents might include company certification, quote requests, etc.
You can view all the documents by company. Select 'documents' and key in the search criteria. All documents for the searched company will be displayed.