Does this sound like you?
You start blogging and post a few favorite recipes. Maybe your smoothie, your oatmeal, your wrap. But pretty soon, those run out, especially if you do most of your cooking from cookbooks. You're cooking tasty, healthy food every night, and you want so badly to share those recipes (that aren't yours) with your readers. But should you?
The short answer is no. While it's not possible to patent the actual recipe, you're still stealing intellectual property, the writing, when you post a recipe word-for-word (even if you give the author credit).
How bloggers get around the law
The simplest solution, one that's ethical and still provides some value to your readers, is cooking recipes that you find online and linking to them. Posting your own picture of the food and telling your readers about it removes a lot of their risk in cooking a new meal; they see that a "real person" cooked the meal, enjoyed it, and didn't blow up her kitchen in the process.
I see bloggers employing a (slightly sneakier) method for sharing a recipe that isn't online — adapting the recipe. When you change a few ingredients and reword the recipe, you're probably doing enough to get around the piracy laws (not to be taken as legal advice, by the way). But here's the problem with this: Authors hate it! Not only is it very close to stealing, it also affixes their name to a recipe that's not exactly as they intended it.
You probably have the decency to credit the original cookbook author when you adapt one. But don't think that just because your blog is small, nobody's noticing that you "adapted" their recipe. Just like everyone else these days, authors and publishers have Google alerts in place that tell them whenever their name or book is mentioned on the web. Even if your blog has fifteen readers, someone is noticing your adapted recipe.
The best solution
You know that old saying "Honesty is the best policy?" Well, it's a saying for a reason.
The best thing you can do is email the author (or publisher, if you can't find an email address) and ask if you can post a few recipes. Often they have rules that allow bloggers to post three or five recipes, exactly as they appear in the books. Sometimes only specific recipes are allowed; other times you're free to choose. A few especially nice ones will grant you permission to post as many as you want!
Simply write a nice email telling them a little bit about your blog, and politely ask. The worst they can say is "no." (And if you're really bitter, you can blog about that.)
Posting recipes from books, citing the source, and writing "posted with permission" alerts your readers to the fact that you're providing them with something of value. Something they can't get for free anywhere else. You can even post a few affiliate links to say, Amazon, and earn some money when they decide to purchase the book after trying a few of your recipes.
The best part: When you email an author, you establish a relationship with him or her. Authors tweet about your recipe posts. Some offer to do interviews. One such interview led to a publisher's adding me to their mailing list for reviewing their new vegetarian cookbooks.
Good things happen when you tell the truth. It never hurts to ask.