The book I am liking right now is Driven Dressage for the Single Horse.
Driven Dressage with the Single Horse is an awesome book. Don't be "afraid" of it based on the title. There is extremely good information in there for even the beginning driver. And it doesn't break the bank, either.
Another one I like is Carriage Driving by Heike Bean. It isn't necessarily for the complete beginner because it goes beyond "pull the right rein to go right..."
The Essential Guide to Carriage Driving is a good book for beginners.
On the Box Seat is another one that really gets into
good driving.
I really like the DVD set from Mary Ruth Marks, Teach Your Horse to Drive. Again, it goes beyond the title. There is info on harness fit, reinsmanship, and driving safety.
Muffy Seaton has some good videos on Harnessing and Hitching, Presentation and Turnout, and Intro to CDEs. Her Bending the Driving Horse is good, too, but her technique is completely backwards from what other World-level clinicians use and what works for me. It can work for some people, though. And the principles are good.
The nice thing about the above books and DVDs is that they are authored by people that are proven carriage drivers. Other authors can have a different slant, such as draft horses, which can be
completely different from light horse driving. Breed show driving is also completely different from carriage driving.
Myrna