Removing fields from Content types - Openpublish

Hi

I am a newbie to openpublish and have been playing around with it over the past few days. I don't know much about coding although I am willing to learn. I am looking to launch a citizen journalism site similar to www.blottr.com. I would like authenticated users to be able to submit 3 types of content:

1. Blog posts / stories
2. Polls
   3 slideshows

I want the "Create Content" pages to be as simple as possible. However, I have not found a way of removing Input Format, Geo tagging, Calais API, and other fields from these content types. Even when I create a new content type they are still there. Does anyone know how to do this? I basically want the different content types to only have the necessary fields - for example blog entries to have: Title, body, add images and a category selector, but nothing else, so as not to confuse users. I would also like the teaser to be generated automatically.

I would like to achieve something like this for a blog post / story page (minus location section and with my own custom categories):

http://www.blottr.com/node/add/story

Any ideas on how these things can be done?

Thanks a lot!