All the research that I've done over the past few years has led me to recommend one specific online guitar learning website: Guitar Tricks.
I personally just renewed my yearly membership, and I couldn't be happier. In my opinion, they offer the best online guitar lessons right now.
What's great is that you can actually start for free. They offer a full 14 day free trial which I recommend to everyone who's looking to get better on the guitar.
Activate your free trial today!