I really appreciate everyone's words of wisdom and advice. I am taking it all in. For instance, I taught myself to change my tire and intertube and oil my chain (I'm handier than I thought - thanks, YouTube!!). I have been checking my tire pressure frequently (it really DOES make a difference!!). I've been making do with some comfy clothes I already have and I'm comfortable so far. Last week I took a day off work to test my route to and from work. Heading in it took me about 1 hour and 40 minutes (and that's with stopping for water twice [need a bigger water bottle] and stopping a couple times due to shifting problems). The ride back took about 1 hour and 30 minutes. I stopped into a bike store and one of the guys there told me I was nuts to ride that route on a mountain bike hahaha. I'm not thrilled about the potholes and sewer grates on the main road I have to take to get to work. I think I'm going to drive partially and then bike the rest to work. At least for now... things will change in the future as my work situation changes.

I did read that Ride to Work book even before I posted on this forum. It was a big inspiration to get going on this.