i'll probably repeat much of whats been said already, but...
when i hit 40 i did the same. i bought an argos classical guitar out the local paper for 12quid, did a bit of www/amazon research and bought this book as it suited the style of music i liked...
http://www.amazon.co.uk/Acoustic-Guitar-Method-Complete-Techniques/dp/1890490555/ref=sr_1_1?s=books&ie=UTF8&qid=1321632067&sr=1-1
... after a few months and having learnt to play a few chords i went out and bought a new acoustic, tried quite a few in my budget and settled on a simon & patrick that felt nice to play and i liked the sound. i'll state the obvious, but i was amazed at how different each guitar was both in terms of feel and tone.
anyway after a long while i hit a wall, got bored and my playing tailed off. prob i found was that my book was teaching me one thing, but i wanted to go play some dylan or bowie maybe and i could play the chords but could'nt figure out the strumming.
last year i discovered lessons on you tube. great. so now i go find a song i want to play and learn it.
if i had the patience and discipline i would sit down a few times a week and practice, either from one of the many books i've bought or via justinguitar lessons. i KNOW that i would be a million times better if i did. but i'm lazy!
if i was starting again, or indeed if i could afford it now, i would have lessons.
anyway, ramble aside, i'll give you one piece of advice... go buy a cheap guitar either from argos or the paper and just get on with it. even with a small bag of chords and super basic skills like i have i love it.