Critique Circle is a fantastic website for those seeking critiques of their work. Here's how it works:
When you sign up you get some free credits. These are needed to post a piece of writing to a genre queue - The Newbie Queue, General, Fantasy, Science Fiction, Women's Fiction/Romance, Children's/Young Adult, or Mystery/Horror. It costs 3 credits to post a piece of writing to a queue. The piece can be as long or as short as you like but anywhere from 1K to 3K is a good ballpark figure. Pieces which are too long can be off-putting to critters (those who critique). Submissions can be individual pieces like short stories or chapters of a novel.
Then, for the period of a week, your submission is open to being critiqued by any of CC's members(3,000 active members at the time of writing this). Now why would a complete stranger want to critique your work? Answer: to earn credits, which they need to submit their own work.
The system works really well. Of course, you will come across some members who are only critiquing your work for credits, but if you hang around long enough you will meet some great people who are genuinely interested in reading your stuff and helping you.
But you've got to work at it. There is an unwritten "you scratch my back and I'll scratch yours" rule which implies that if someone critiques your work you should critique theirs. It can take months to find genuine critique partners but the effort is time well spent.
Five years later I have a small team of diverse crit buddies who read everything I submit, and I in turn do the same for them. The anonymity of the site allows readers to be more honest than in a face-to-face writing group. Each of my crit partners have a particular skillset, some have superb writing instincts, others act as the grammar police, and others critique as readers.
I've reached the stage where I don't post writing to public queues anymore. As a paid member, I can create my own queue, which can only be accessed by those I invite.
As well as being a place to critique and have your work critiqued, CC is also a community of writers with interesting and active forums on all topics, as well as helpful writing tools and links.
I honestly couldn't recommend Critique Circle highly enough.