Lane,

...what catspaw said. You won't believe what a treasure of threads there is on this topic!

I am a huge fan of regular Drop-D (where only the low E string is lowered to D). At times I feel like that should have been "standard tuning" for the guitar -- like when I'm playing "Butcher Boy, Shady Grove, Soldier's Joy, Red-Haired Boy, even Arkansas Traveler -- it's a tuning that can make all those fiddle tunes sound fuller when playing without accompaniment.

The easy way to deal with the chords is to simply play all the regular chords but remember to accomodate for the two step jump on that E string -- thus a good G is 550033

Another way to get that pleasant drop D sound but not have to alter your regular chording (left hand) is to either turn a Kyser capo upside down and cover the A through high E strings with it at the second fret (kyser and others make a shortened capo for this -- you can pay more for it or saw one off yourself if you like the sound).

Some tunes I play in Drop D that many don't think of as drop D --
Castles In The Air --McLean
Lighthouse and Millworker --Taylor
St Judy's Comet --Simon

Have fun!