If you want to send people to a generic page or to a listing of all projects they have been assigned to, you can send them a link to the “address” folder your projects are located at.
So if a single project address is http://www.yourdomain.com/panorama/website-redesign-for-company-xyz you’d send people to http://www.yourdomain.com/panorama/. Once logged in, the user will only see a list of projects assigned to them (unless they are a project manager or administrator.)