I would actually take fit a little more seriously that that. Try to find a copy of Lennard Zinn's "Zinn and the art of Road Bike Maintenence". Get it from a library if you can. I'm not a big fan of most of this book, but dude is, well, a zen master of bike fit. He has a section on bike fit that can save you a ton of knee, back, elbow and neck pain.

The book will guide you through a few measurements of your body and give you a good place to start. If a length is a little off here and there, you can still fix it by switching out parts, but it's best to get a frame that will start you in the right direction.