First of all, I always recommend buying from a Local Bike Shop. (LBS) Stay away from the big box stores, such as Walmart, Target, REI or Dick’s Sports. Buying from a local retailer will provide you the proper assembly, fit assistance, selection and service you won’t get at a department store. Not only are the bikes at an LBS superior, they are assembled by mechanics, not stock boys/girls. A properly assembled bike requires about an hour of work by a trained mechanic who will adjust the brakes, gears and bearings and make sure the bike is properly adjusted for your enjoyment, fit and safety. I often see bikes from department stores assembled so poorly they are too dangerous to ride.
what to look for fit, wide selection, more
On your search for a new bike, you may happen across a salesperson or bike shop made up of bike snobs. Stereotypically, these guys would spend more on their bike than you, as a beginner, would ever dream of. They may direct you to the greatest bike in the world for its intended purpose, but if it doesn’t fit your intended purpose, there is no point in buying. Some bike snobs may not appreciate a bike made for the family rider because in their world, everything is about performance. If they sold cars, they would direct you to a Corvette, when you asked for a minivan.
Don’t confuse bike snobs with those who may recommend that you consider spending more than what you originally intended on spending. A shop may recommend a higher priced model not because they are trying to upsell you, but becuase, based on what you described you planned on doing with the bike, you require a higher quality model. Most shops do not pay on commission, so upselling you isn't likely the salesperson's priority. Use your judgement. If a bike shop isn’t listening to you, go elsewhere.