Personally I would recommend you to start with a tutor. I'm a qualified music teacher myself and to be honest, it's much easier to show and teach someone from scratch rather than correct problems and any bad habits they might have picked up.
There are good tutor books out there but there are some real stinkers too. Used in conjuction with a tutor, you'll be in a much strgonger position to learn. And you'll do it quicker too so you won't lose interest that you might do on your own. I'm not much of a guitarist myself. I studied Piano and Double Bass, but I would seriously consider starting with a Tutor. Little things like tuning etc may seem straight forward but you'll come on twice as quick with someone to guide you.
Whatever you decide though, good on you and I hope it brings you half the pleasure it's brought me. Good luck.