If you're lucky enough to have friends and family who are willing to read your story, let them! But just know they are likely to praise the fact that you completed a novel, instead of the story itself.
Once you've tried the family route, you can look for beta readers online or through writers' groups in your town.
Personally, I feel uncomfortable letting people I know read what I've written. Ask my husband. He doesn't even really know what ...Until Alex is about. He's more interested in hearing if there are any racy scenes...
Lucky for me, I found the amazing writer, editor, blogger extraordinaire--Stephanie Elliot. If you do not know Stephanie, please check out her novel What She Left Us and her novella The Cell Phone Lot. You will not be disappointed. Stephanie has been a lifesaver for me. I was stuck in a rut-editing my story everyday, but I wasn't changing the story. I was only changing word choice.
I needed her to point me in the right direction. From our first correspondence, she pointed out a huge hindrance in my story. This was before she even agreed to read my manuscript! Without her pointing out the flaw, the story would have read differently than what I wanted. I could not have asked for a better editor.
While Stephanie has been editing, she has been sending me short notes with reassuring comments and pages she completed. This gave me two things...confidence that I did not have, and an idea of where she was in the story, so I was not just sitting home biting my fingernails wondering which page she was on and what she was thinking. I really appreciated those notes. So until I get her full comments, I will be waiting patiently.
If you are interested in a real partner through this process--someone who is kind and a real cheerleader, contact Stephanie at www.stephanieelliot.com or firstname.lastname@example.org.
(Much of this information can also be found under About Self Publishing)