Ah, you are off to a good start. Four years ago, I was in your shoes. Except I had an old crappy hybrid bike in the garage, which was the perfect bike for getting over the "sidewalk and MUP phase" of a new commuter and rider. It didn't take long to graduate to road bikes. Spend as much as you want to on a bike, but do your very best to get it to fit correctly. If that means paying a bit more, it will be worth it. The fit will be more important than the purchase price.

It appears that you have singled out road bikes as your preferred tool. Therefore you are in the correct form, and I commend the choice. It will not be long before you are taking the long way to and from work, and riding even when not going to work. The commuter forum has lots of info in it, but the atmosphere is decidedly different in that forum.

I presume you have determined the route you will be using to commute on? No point in getting a road bike with narrow wheel clearance if you have to go long distances on gravel roads or trails, where a wider tire would be beneficial. You should also determine what you need to carry with you to commute. If it is just yourself and some water, any bike will do. Need to carry a laptop, lunch, clothes and other supplies? Then make sure your bike frame is drilled to bolt on a rack. Sure, you can use a backpack, but racks are better.

Need ideas on how to split up a commute between rail and bike, bus and bike, or strategies for commuting in the dark, securing your bike while you are at work, or situations where work has no lockers, showers, cafeteria, or when cycling attire won't be acceptable? Check out the commuter forum.

edit: FWIW, I commute on my Specialized Roubaix. I have an entirely paved route, and I only have to transport myself and water. Lockers, showers, food, secure bike storage, and clothing are provided at work.