Where do Perez and the like get all their material?

This is a new blog for me...something I thought about doing last year but didn't until now. I'm wondering how blogs like Perez Hilton's Perezhilton.com get their material? That blog is a bit too "much" for me (calling people sluts for publicity isn't my thing). I don't want to sling mud (that may not even be true) to get people to my blog. Do the authors of these popular blogs have direct phone lines to celebrity PR people, and to celebrities themselves? How? I wonder.