If you are about to deploy Project Server 2007 and more specifically Project Web Access 2007 for the very first time, then you need the following guides.
Walkthrough: Deploy Project Server 2007 to a server farm environment
This is a four part video that shows how to install Project Server in a new WSS environment. Pay attention to Part III:
Part III describes how to add additional PWA sites, including:
Creating a PWA site with empty databases
Creating a PWA site that connects to restored databases
Creating PWA site that connects to a restored database is especially important part. It comes into the game when you need to do Disaster Recovery of PWA 2007 site from my previous post.
The cool thing about the walkthrough is that not only the video will show you a real demo how to do that, but also there are .docx and .pdf documents with all the steps in the demo which you can follow one by one after the demo.
If you need to deploy Project Server 2007 or PWA 2007 site in an existing MOSS installation, use the Deploy Project Server 2007 to an existing deployment of Office SharePoint Server 2007.
To use a brand new MOSS installation, use the Deploy Office SharePoint Server 2007 and Office Project Server 2007 to a new environment guide.
If you only need to move a PWA database to a new, dedicated, standalone WSS content database, use the Extract Project Web Access site data to a new content database guide.