Becoming a surrogate

I am thinking about becoming a surrogate. My two best girl friends who happen to be spending the rest of their lives together happily in love, both have medical issues that prevent them from carrying a baby. Has anyone ever gone through the rewarding adventure of surrogacy? How was it for you? I know this may be a strange question and not too direct. I guess I'm just trying to get any info and advice as I don't know someone who has gone through this. Thanks