On the inside, the Leuchtturm has a page dedicated to your name and address, a blank page, and then another page that has a pre-printed table of contents. This is really useful, and I know that several people have mentioned that this is really handy when using the Bullet Journal method. The back cover has a sturdy pocket for holding loose pages, which I've never used. Pages 107-121 are perforated.
One of my favorite features is the page numbering. Yes, the Leuchtturm notebooks have the page numbers printed in the bottom corner of each page in a light gray ink. I number all my notebooks, and this is a huge convenience for me.
The book also came with a sheet of stickers that you can place on the front or spine to label the notebook. I haven't used them yet, but plan to once it's full and I store it away for reference. Another cool thing that is included is a ruled card that can be placed behind the blank page so that you can have a rule to follow on the page. I haven't used it, but it's a nice thing to include. I have a plan paper version, and I'm not sure if they include this card with the other types.
Like I said, my notebook has plain paper, but this seems to be slightly difficult to find sometimes. Goulet Pens has a softcover book, but only with lined paper. Amazon has the Large Squared Soft Cover, which I'm sure Brad is all over.
Now, on to the paper.