Rails is very "do it the Rails way" about putting together a website, while Django lets you kind of do whatever. If you're a beginner, the do whatever part of Django can often lead to very kludgey code and a big mess if you don't take the time to carefully architect out your application.
Rails is also nice because it's very strict MVC and built for the modern web (meaning it's easy to have a model spit out it's values in either JSON or be plugged into a template, for example). With Django there's alot of fiddling and "what file do I put this function in?" (for the beginner).
Plus Rails has super duper good form handling, while I find the form handling on Django to be atrocious.
I think your choice should come down to how well you know the architecture of the application you want to build. For me, I find it easier to shoehorn my application into the RoR framwork than to try and shoehorn the Django framework around my application.
(FWIW, I'm speaking of Django 1.6 and Rails 4. Things may have changed in the latest version of Django)