I will second that - good reply Beerman.
Unless someone in the house understands bikes, I would also direct them to a local bike shop for their first purchase instead of online. Online is cheaper, but your local shop will usually give you QUALIFIED service free for the first month, or even year, that the bike is owned. This is invaluable as the number one reason why bikes break for beginners is because they are not properly maintained.
There are a number of sub- $300.00 bikes that are of good quality (not great), that will do very well for an entry level rider.
Wal-Mart type bikes are bad because they are kids bikes, truly designed for 10 year olds. They put pegs on the bike, but they aren't supposed to actually be used for anything. Those bikes are actually very dangerous because no amount of maintenance can ever make them safe. They are like a Yugo - unsafe at any speed.