Yep, ya can definitely teach yourself. But some of that answer will have to do with what you intend to get out of your playing in the future.
If you just want to play songs and get a band going, you can probably learn most of what you need just emulating other players on your fav CD's and buying a couple of decent books.
If you want to become a pro session musician tho, you're gonna need a lot more theory and sight reading, so lessons would be more advisable.
Either way there's quite a few of us here who never took lessons. These days it's a lot easier to learn how to play cause you have the internet to get your info from. When I was in my teens all I had was a cheap Lloyds record player and a Van Halen album.