Another list of sites for writers worth looking into: Best Social Networking Sites for Writers, by Kurt Chambers. Very comprehensive list.
Instead of making my own extensive list of great websites for writers, I decided to link the ones I've found (which are already pretty good), and just highlight my very top five favorite sites in this post.
My Personal Favorites
Twitter is a great place to
Writing.com is where my MG/YA novel critique group lives, and where most of my short stories were born. Here, you can upload your poems, short stories, chapters, or any other writing-related items in your portfolio, for people to read and review. You can join specific groups, participate in contests, enroll in writing challenges, and get gift points for reviews you give. The basic membership is free, but I would recommend you get an upgraded membership for $50 per year, which allows you to post more items and gives you access to more functions, like hosting your own group or contest and starting a blog.
Squidoo is a good place to post articles and get paid for them month after month if they become popular. An informative blog post could easily become a Squidoo article and generate more exposure and possibly some cash. Not much, I must admit, unless your article becomes widely popular, but it's still better than nothing! And if you know a little bit of HTML, you can customize your article to make it stand out. There's also a member forum where we can exchange tips, ask each other questions, or just hang out.
The Free Dictionary is a site I use a lot while writing, reviewing, or editing. It shows word definitions from various dictionaries, pronunciation, synonyms, translation in various languages, and much more.
WriteOnCon is a free online conference held once a year, during the summer. The event is focused on kidlit (picture books, MG/YA) writers, but a lot of the information can be used by any other writers as well. The conference includes interactive panels with agents and writing professionals, a forum for participants to interact and review each other's sample pages (with possibly a few agents lurking around), articles and lectures about the different aspects of writing, and contests and prizes. The best thing ever! And it's totally free!
Other Sites Worth Mentioning
There are other sites I'm member of but don't use as much as I would like. As an extra, I'll give a brief list here.
SCBWI - a society for children's writers, offering conferences, writing resources, local groups, and discussion forums
AbsoluteWrite Water Cooler - a forum where writers mingle and have ongoing conversations
Book-in-a-Week - a writing challenge where participants decide their own writing goals for the week and aim to reach it
Goodreads - a place to share about the books you read or are planning to read
LinkedIn - a networking site especially useful for freelancers to connect with people in the same industry
What's your favorite site for writers?