Yes it is a good site. Another good site I use for reference is: http://www.dmv.org/custom-built-cars.php
I would not use either site as absolute, current and correct info. But they are a good start. After using thes sites, you can then move on to your state's site and search for passed legislation and for pending legislation.
I urge all builders to check these resources to verify that what you are planning, can indeed be done in your state and how. If your state does not currently support the car hobbist, and legislation is pending, then contact your senators or representatives directly and let them know you are interested these bills being passed. Unless they hear from us, they cannot possibly know what the people (us) want and how they should vote.
Illinois passed a bill in 2002 allowing for replica vehicles to be built. With this now being 2011, they have had 9 years to work out the procedural process, still, I am 3 months into the registration process and counting. The registration process does not go quickly when you are building a car from scratch. Illinois has one person for the entire state, who's responsibilty is to process the paperwork requests for Street Rods, Custom Vehicles and any other Specially Constructed Vehicle.