I think when you are first starting out, you do start with family and friends. Then you need to figure out where other writers are. Like here in Portland, Willamette Writers is always listing critique groups in its newsletter. Or you could look online. If you blog, you might blog about wanting to start or join a group and ask people to email you offline. If you have a friend who is at the same stage of the publishing process, you could ask if you could share critiques. I think it helps to prepare a list of questions to guide them, ie, "Were there any places where your attention flagged?" Some questions it's better to ask after they've read the book, ie, "Do you think it was episodic?" because the question might color their opinion.
My first book was probably read by my mom, my good friend at work, and my agent before it got published. It still amazes me that I have fans whom I have never actually met.
What do you want to know?