The source of the information posted by hawk is the CFS (Child & Family Service) The website is here
May I also suggest you read through the Philippines Republic Act No. 8043
AN ACT ESTABLISHING THE RULES TO GOVERN INTER-COUNTRY ADOPTION OF FILIPINO CHILDREN, AND FOR OTHER PURPOSES.
Also worth reviewing is the document IMPLEMENTING RULES AND REGULATIONS OF REPUBLIC ACT NO. 9523 as it explains eligibility and the processes to follow from the Department of Social Welfare and Development (DSWD)
Sorry if it looks like a lot of reading, but it's not too long and you'll find it invaluable as a guidance.
Good luck
