Finding someone who will consent to read your baby for free, and give educated, but kind advice is probably about as hard as finding an agent or a publisher.
However, there are avid readers on GoodReads who have formed a group where you just might be able to find a few who are willing to read your baby and so forth.
It looks good, and certainly well-intentioned. I haven't met anyone who has tried this, either on or off the internet. Any comments from those who have?
The invaluable Belinda Pollard has a few more ideas on her Small Blue Dog blog.
Number one is a very strong suggestion.
JOIN A WRITERS' GROUP
Not only will they critique your work, but they will tell you if it should be writers' group or writer's group.
I have mixed feelings about writer's (or writers') groups. I have talked to some, and have always wondered why they are sitting there listening to me instead of sitting at their computers or lined jotter pads, or whatever. You know what I mean. Writing.
Also, there are jealousies involved. Rosen Trevithick has a very funny portrayal of a writers' group made up of competitive women in her very funny book, My Granny Writes Erotica. As we all know, women can be catty, in thought if not in actual word.
It is also only going to work if the other members are keen on the same kind of writing that you are. It is no good belonging to a group if you write techno-thrillers and they write hot romances -- unless, of course, your character list includes a few passionate robots.
Part of the job of a BetaReader is fact checking, which means that if you are writing a novel about scuba divers, you're not going to get much out of experts in flower arranging. So, be careful about what kind of writers' group you decide to join.
Another very good idea is to use social media. The GoodReads group is only one example of what you can find on the internet. LinkedIn has similar groups. Those people you chat to through twitter, Facebook, or by email might develop enough interest through hints you've dropped about your book to want to have a look.
An idea of my own is to ask people who have a special interest in your area -- scuba diving or flower arranging or whatever -- to supply a blurb. Flattery will get you everywhere, and in the process of composing the dozen words you will proudly display on the back cover they might drop a few hints that will help when polishing your final draft. They will certainly tell you if you have any of your facts wrong.
Good luck. And remember to be politely grateful.
Because they can use social media, too.