On ARC (Advance Reading Copies) And Such..

I was wondering if anybody can help me on how to get Advance Reading Copies (ARC) of books and free copies from newly released books for PNR and Urban Fantasy authors? Do I contact the publishers? Do they have some criteria before they send you these books? I plan to giveaway books to my blog readers from the Philippines especially since books are usually released here like 1-3 months later than U.S. release dates..yeah so sad :(
If you can help, I would greatly appreciate it!