create mysql table, display data on php page

Currently we have a database with many tables. One of the tables has a list of companies. We want to create another table which lists products. Each company sells one or many products. We need a secure user interface to link the companies with the associated products. Please propose a rough sketch of how you would design this page and how it would work. We also want to develop a secure username/password table which we can use to access the secure user interface discussed above. And will use this same table to access other secure areas of our website for which currently each user uses various usernames and passwords. Deliverables: 1. New mysql product table. 2. A secure and hidden web page to link the companies in the company table with the associated products they sell in the product table. 1 company to 1 or many products. 3. New username/password table that will be used to access the company product linking page. Ideas to keep in mind: 1. The username/password table will in the future be used to access other secure areas of our site. Not all users will have access to all secure pages. 2. The product table is the first along these lines. If this is implemented well, we will be expanding to do a very similar linking of Brands with the companies. 3. The web page for linking companies and products should be expandable to incorporate linking brands as well in the future.