What are some good online sources for recipes? Please specify the type of recipes the site has (extract, all-grain, mead, cider, etc.).
Hopville lets you save recipes... it's not just a source of them, I often find that I can't find exactly the ingredients in a recipe. Also it will guesstimate Initial and Final gravity, color and other useful information.
I find this forum to have some good beer recipes. Two of the good threads below
Beer, mead, cider, and wine recipes, including national award winners...
See these recipes from the American Homebrewing Association.
I see I'm a bit late in the game here, but I would nonetheless recommend Brewtoad to anyone who's looking for new recipes or would like to share theirs.
You can post recipes to share or browse recipes posted by other brewers. It's a really neat site with excellent UI/UX. You can even see what color your beer will be as you tweak your ingredients, and once you've settled on a recipe you can order the supplies in a snap.
Brewers friend has a nice list of recipes that you can look through and sort by many different criteria. They have tons of useful calculators and a recipe designer as well.
There are tons of other useful things on that site besides what I have listed above, but those are the places I go most often there.
Just started a site for Cider brewing and adding my tested recipes frequently. Please take a look and let me know what you think.