They are pretty much equivalent cameras and both good cameras.
The Nikon is slightly newer, but they both still use the same sensor as their predecessors. Giving the same picture quality.
It comes down to your price range for what camera model in any given brand that you purchase and if this is a hobby or passion.
The most important part of any dslr is the quality of the lens rather than the camera body (for the most part).
You should read this before making any decisions: http://www.overclock.net/t/898709/for-new-dslr-users-a-beginners-guide
Read this and it will allow you to have an informed decision, or at least be able to ask exact questions that you can receive a detailed answer to.