Nikon D3100 help [tooshort]?

I just bought my first camera (upgrade from a point-and-shoot). I bought a Nikon D3100, and I have a few questions.
1. I bought a 55-300mm lens and when I use that lens, it's somewhat blurry. I switch to my 18-55mm, and it works fine. Why is my 55-300mm blurry?
2. Whenever I went into playback mode, it shows the picture in a small corner on the top-left, and on the right, it shows some levels stuff. How can I view the whole photo?
3. When I bought the 3100, it said it came with the GEO coding, the gps thing. Can I get more info on that, and how to use it?

If I have any more questions I can think of, I'll be sure to edit this post.
Thanks.

Added (1). I did read the manual. It confused me.

I bet your manual feels neglected.

Read the manual.