Entertainment Blogs:

Deadline Hollywood - Nikki Finke's blog on the most up-to-date entertainment news
Buzz Sugar - Fun entertainment blog with polls, pics, etc, geared towards more youthful audience
Hollywood University - Great information resource for those wanting to pursue a career in entertainment
Amanda the Aspiring Writer - Writing tips/advice from aspiring screenwriter (for agency assistant)
Complications Ensue: The Crafty TV & Screenwriting Blog - Working screenwriter, Alex Epstein writes about the writing craft
Stephtvfilmwriter's Blog - Blog of an aspiring writer (entertainment and non-entertainment related posts)
Eureka Unscripted - A blog written by the writers of Eureka about the show and writing in general
Jane in Progress - Writing tips from accomplished TV writer, Jane Espenson
This is Your Pilot Speaking - TV Writer blogs about pilot writing
Show Me the Screenplay - Blog/site written by Manager on how to break into entertainment
Hollywood Writers' Office Assistants Social - Blog for people working on TV shows, lots of industry interviews
Go Into the Story - Screenwriter interviews, trivia, and other fun movie stuff
Carvings - Aspiring TV writer blog
The Anonymous Production Assistant's Blog - Blog about being a Production Assistant - Production Assistant info blog
Script Goddess - Script Supervisor blog

Friends Blogs:
Art Star - Arts blog with many wonderful posts by the lovely Amy Kristen
Craig Ormiston's Blog: Collected Thoughts From a Cultured Fool - this one is all explained in the title (entertainment and non-entertainment/life wisdom posts)
Ride to the Top  Blog about making it in the entertainment industry
Legally Crafty   Future law student makes crafts out of quite unusual items