I'd recommend the LBS too. They will measure you and tell you exactly what size bike will fit you properly, and talk with you enough to find out what you really what to use the bike for, and suggest what might be a best starter bike for you. (An improperly fitted bike is the main reason most people ride a few times, then put the bike in the garage forever.) And, they won't sell you a piece of junk. It's not good for business. They want you to come back--happy. Their bike will be a little more pricey than the big-box stores, but not really when you consider that within a few months of buying that cheap big-box bike, you'll be replacing components, so you're not really saving anything by buying cheap. The LBS will guide you to some low-end bikes that will make you happy. Plus, they'll even teach you how to ride it, how to use the shifters, basic maintenance, etc, some riding techniques too, and all for free.