Even if there's no time/money for weekly lessons I'd suggest finding someone to give you occasional lessons.
I had one guitar lesson - 2 years ago - to make sure I wasn't doing anything inherently wrong from the get go. That was pretty much the first time I had even held a guitar.
Then - I let it all slide, until last month when I got a new guitar. I've messed about with it on my own (with books!) but now I have more questions that need to be addressed by a professional - so I will book another lesson. I don't want to go too far off track.
In short: You just cant "see" what you're doing wrong on your own. And since we all tend to practice what we find easy (even if it's wrong) and neglect what we find hard, when we don't get guidance we can rapidly just learn to get really good at doing it all wrong. And relearning to do it correctly is very difficult.
I play other instruments - and I've started teaching beginners (NOT guitar
) - so I'm coming at this from a number of angles...