FH and I had our first dance lesson at You Should be Dancing (8th Ave & 31st St in Manhattan).
We had some problems getting started (miscommunication about scheduling -- be sure to confirm your appointments if you go there), but everyone was super-nice.
Our instructor, Dragan (yeah, that's his name) was WONDERFUL!!! In our 1/2 hour trial (which lasted more than 45 minutes) he taught us the basics to 5 ballroom styles and gave us a sense of what our first dance would look like.