Do i need to create a business for my blog?

I am creating an entertainment blog, kind of like TMZ, and eventually i plan on making $$ (im not basing my career on this blog but i hope to earn something) anyway, do i have to make my blog an official business. For instance if my website was blahblahblah.com would i have to create a blahblahblah LLC (or whatever) and register it w/ the government and all tht good stuff?