Go to your LBS and get them to recommend something..when you have the money..I find most of them to be really knowledgabe..

Riding a Wally Wold/Dept. Store bike compared to a real bike shop bike(what I call a 'professional' bike) is like the difference between night & day. Just about any bike from a real bike shop is a pleasure to ride and while you're at work you're just itching to end the day and get back on for the ride home.. it's like the first time you drive a car to work...you can't wait for the day to end so you can get back in that car and zoom around.. I was really fazed by the cost of LBS bikes at first but when you compare a $28,000 vehicle (car) with a really good $2,800 bicycle (not including insurance/gas/wear&tear/depreciation) that two grand starts looking like a real bargin..

Okay enough of my rambling...Great on your first commute!! Keep going!!

Cheers!