I have seen sites that have hundreds of recipes and different diets. They also update them daily with new content. Where do they get this content and how would I know if it's legal to use this content on my site?
Well, I run recipe sites, and am planning on adding more. I get my "seed pack" of recipes from buying the rights to a package of them, or receiving the rights as part of a promotion. I know they are probably used on other sites (whether legally or not) so I customise, edit, polish, improve, etc them before posting them. It is labor intensive! I also add my own, create variations on existing recipes in my database, and solicit entries from readers. I start off by plugging in (preferrably) about 100 recipes for roll-out, then try to add at least one a day (updating my google sitemap each time, natch). I pace it so that I don't run out of recipes too soon, so G sees that I post daily. I'm quite certain that with a black-hat, churn-and-burn strategy you could do it all a lot quicker and easier, and probably more profitably. But I, myself, enjoy what I'm doing, so I'm building to last.
If you are scraping recipes off of other sites without permission, its definately not legal. One of these game cheat sites sued another one a few months ago for doing just that. Whether you will get in trouble or not, who knows -- but if someone does own the copyright and decides to go after you plan on losing your house. Your safest bet here is to publish user submitted recipes.
How would you know if a user was submitting a recipe that was copyrighted? Just curious, because I am always looking for new recipes on the web and I do run into quite a few duplicate recipes. Not sure if it is coincidence or it was copied. What if you put a link with the recipe to the originating site and gave them credit? Just a thought.
Being in the clear regarding rights is very important. However, accepting submissions from readers does not assure anything. THEY may not own the rights to the recipe they submit! One source that is free and clear is out-of-copyright cookbooks. They can be a treasure trove, but don't expect to find "Pan-seared Ahi tuna in mango-lime salsa" there, though! It's more like: "Kneade dough verily with fatty lumps taken from the hindquarters of a goodly steer, add three hanks of corne-butter and cooke in the usuall method."
Insufficient without permission. What you could do, if you are not certain as to the provenance (good word, eh? ) of a recipe is change it. It's OK to have a variation, or recipe inspired by another recipe. Every recipe in existence is a variation on another, in fact. I DO recommend not simply re-titling the recipe or merely changing one ingredient, or quantity. Make it unique in a meaningful way.
My understanding with recipes is that the ingrediants can't be copyrighted, but the method of of putting the ingrediants together can be copyrighted. So...you can't just go in a pull recipes from anywhere and not expect to get into trouble at some point in time. Like most things, you have to modify or buy rights to some recipes. Your better off spending the time up front and get the correct scope yourself, before you get going to far.
Maybe you can visit article submission sites like Ezine and some of the Yahoo article-announce type websites to find recipes? The authors give permission for reprint. I don't know how this will affect your website in terms of dup content though...one of the gurus can help on that.
Take a look at a site like GameFAQs: http://www.gamefaqs.com/console/ps2/code/583527.html Notice how at the bottom every cheat code says "Contributed By" Talk to a lawyer (who knows internet law) about that one if you want to know more.