I prefer the 12 x 12 3 ring D binders - then if some of the pages are a little "fluffy" its okay. I am a flat scrapper, meaning that I use embellies that are pretty flat but still, the edges of my books were much wider than the spine and I didn't like that. They didn't look right on the shelves with the edges so much wider than the spines - but that is my opinion. Not as much of a problem with the ring binders.
Also, with the ring binders you can move things around eaisly and with the posts - I found it to be a nightmare.
Everything is how you want it. There are no rules.
If you have an Archivers or Michaels or other scrapbook store near you or store with a large scrapbook section they may also have an introduction class for scrapbooking.
I took one at Archivers 5 years ago. It was excellent. It helped me focus on how I wanted to scrapbook. She showed lots of examples of styles and taught us about differnet adhesives, album choices, journaling pens and other tools. It gave me the confidence to get going and start scrapping.