You want to associate people and products to a Project and see everything at a glance.
In the same way as the "Company" tab works whereby all records at the same Company appear on the company tab so you can have a "projects" tab where you enter the project reference and then see all records related to the same project.
edit navbar.html (Admin | Site settings | trouble shooting | templates | navbar.html) be sure to make a copy before altering.
Replicate the entry referring to Company.html changing the wording to your project.html
For support please email firstname.lastname@example.org we will be pleased to do this for you.