If you aren't going to take classes it's be a long road, and most people end up giving up. When I first started I picked up so many bad habits because I was figuring it all out myself. Youtube is full of people giving guitar lessons, so that is one way you could go.
If you do want to get into Rocksmith as a tool try to pick up the bundle that comes with a guitar, I've heard it is a decent beginner guitar and you can find it for under $200 now. Rocksmith should not be the only way you learn, it's tutorials are basic and it never really tells you what you are doing wrong. It is a good supplement though, and it will build your confidence by letting you play songs at your own pace. Plus it has a built-in tuner, which is one less accessory you will have to worry about at first.
But the one thing that really helped me out when I first started playing guitar? Go buy a chordbook with your favorite songs in it and practice it every day. Nothing is going to top good old fashioned hard work.
@gumdealer: Do you think that you'll get a lot of use out of your Ouya and is there a chance that it could become your go-to device for multiplatform indie titles?
If enough mobile indie developers support it and make use of the controller, I could see myself using it a lot. But if I had to choose between an indie game on the PC with a 360 controller or an Ouya version, I would choose the PC version 100% of the time. Most of the reason I picked this up is because I needed an extra media box, the game part is just a bonus for me.
I've had one for about a week now, and it met my (low) expectations. It's not offensively bad, the worst part is definitely the interface, I hope they overhaul it. I haven't had a problem with the controller, but I haven't played any games that try to use all the buttons.
It seems like the kind of thing that you already know if you want or not. It runs emulators fine (except for the DS one, I couldn't get that to run too well) and it seems like the kind of thing homebrew people will love to fudge with. An important thing to know before buying one is that you can't access the standard android app store, there is a dedicated Ouya store. You can sideload android apps into it though, but most don't work too well with the controller and have to be used with the touchpad.