Check out this site. It'll answer many of your questions.
http://santanatandem.com/Started.html It's from Santana's website and they are real flagwavers for their products, but it's very good information. BTW, I own a Santana and love it, but the best advice is to go out and ride as many different bikes as you can. Like a single bike, you'll feel the differences pretty quickly. Tandems East is a great resource less than an hour from your house.