Quote Originally Posted by pooks
Oh thanks. Now I just need to train!

About slicks and other tires -- do they hold up to the road as well? Are you more likely to get punctures?
I was hoping someone else would answer this - be aware that these answers are what I think and someone may indicate I'm wrong.

On the paved road, slicks will last longer than knobbies - knobbies are made for dirt, on the road they are not as grippy (I'm sure that's the technical term) and the knobs wear down. If you've got thorns and road debri, get slicks with some sort of belt, or add goop or something to them. I am very happy with my Conti Gatorskins and Conti GP 4000 (for my "race" bike), they are both holding up to the tackweed we have around here fairly well. I have tire liners in the gatorskins. I have heard lots of good things about the armadillos, but they don't come in the right size for my wheels.
Slicks will (probably) not be faster on dirt, they aren't made to grip dirt. They will also not be as sturdy.
So, if you ride on pavement, get slicks. If you ride on dirt, get knobbies. If you ride on both, try semi-slicks.
Before I got bent, I had a MTB and 2 wheelsets. One was set up with big knobbies for off-road and one with narrow slicks for pavement. Worked pretty well, since I was too lazy to change tires, and it's easy to just swap out the whole wheel.
Be aware, if you decide to buy some slicks, that there are more than enough wheel/tire sizes to confuse you forever, and get tires that will fit your rims.