If you're just getting started I can give clear guidance and one to one interaction that I feel you simply can't get from something like a book or youtube video. Often people who are self taught come for lessons because of some serious underlying fault in their playing or technique that they simply have no way of knowing on their own. It then can become a rather large task to go back and re-learn basic core techniques. Please get a tutor when you're starting out so you can get a clear grasp of the basics before you go it alone.

When you're a beginner, lessons will often be based around learning fun and easy songs that build up all the core skills that you'll need for progressing further, with all the tips and tricks along the way that will let you advance to higher levels of difficulty later on.