User uploaded news website w/ membership registration

I need someone to build a website for me that is a news website but this site is user uploaded. People will come to this website when they want to share a news link to the rest of the world. I would like there to be a free membership so they can do a simple sign up and NO information would be share or sold in order to post. When they upload the link they will also have a list of categories to choose from and they must choose one. There would also be sub-categories for certain ones I.E. Main category would be Politics, and sub-category would be "liberal" or "Conservative" and so on. The links will also be voted on so the top stories can stay at the top. It would also need a relatively easy dashboard for me to make changes... adding categories for things such as the current BIG thing happening at the time. Also when they upload the link they will have an area where they can add there own blurb if they choose. I am a news junkie, and am looking for a site that is unbiased. All the news websites out there show what they want you to see. This site will be for people who surf and want to share with not only their friends but also the world. There is a lot of news out there, and people need to see it. I would also like to integrate this with face book and twitter. I also need this launched and hosted with ease. i am rather computer savvy but not website savvy at all.