well, it starts w/ electric vs acoustic. which one do you want to play. If you want to play acoustic the following will still apply but the guitar recommendations will be invalid:
anyways... the MOST important thing is comfort. Don't worry too much what a sales guy tells you about a guitar's electronics (pickups etc) that's not gonna matter too much just yet. you want to play a bunch of guitars and pay special attention to how the neck feels to you.
many non-guitar-geek folks take this for granted; but all guitar necks feel different. some are big & fat, some are thin, some are shaped like a V, most are rounded in the back etc
if your hand's not comfortable on the guitar don't buy it no matter how cheap or how cool it looks. at a 100% beginner stage quitting is a giant possibility and in my opinion pain & discomfort lead to you not enjoy playing & you'll eventually just quit.
another related note is how the guitar is set up. a good setup on a guitar is the difference between the strings buzz vs the strings being 1/4 inch off the fretboard vs a nice comfortable distance from the frets.
almost any guitar can be setup to play pretty good but at stores (especially a giant one like guitar center) the cheaper guitars aren't well maintained at the store (or come poorly setup from the factory) and are a nightmare to play. at a decent store they should be able to set a guitar up for you. so, i'd highly suggest you ask for a quick tweak if you find a guitar you like but it's strings are a tad too high or buzzy. it should only take a couple minutes and they should do it for free.
the last bit of advice id give is... buy a tuner. cheaper guitars can go out of tune pretty easily (especially w/ new strings). when the guitar goes out of tune most of what you play will sound crappy and u wont get that "woah, that sounds right" feeling when you strum chords or play even simple licks. so buy a tuner and make sure youre in tune.
buy a comfortable guitar
make sure the setup is decent before u pay them money
buy a tuner & stay in tune