Share 'How To Receive ARC's (YA/Teen)?'

Hi!   I've had a book blog for a while now (nearly a year!) and I keep on looking around at many other book blogging sites and a lot of them seem to be reviewing ARC's and stuff, and I was wondering, Where do they get these ARC's? do they request publishers/authors for them? do they enter? I dont know, but I really would like to receive an ARC! so I was wondering, how do I get one?? Thank you so…