Not a professional, but...all of the above. I have bookmarks in books, a bookmarks folder entitled "recipes to try," as well as a ton of saved recipes on the Food 52 and NYT cooking websites. I have a folder of documents entitled "recipes" that I've broke down into categories (entrees, desserts, breakfast, sauces, etc.) with mostly word docs but some jpgs and screenshots. I have migrated over to using the "copy me that" app/website to manage recipes I collect from online sources.
I understand Eat Your Books is handy for finding recipes in your hard-copy cookbooks. I have it, but have yet to index all my cookbooks.....
To me, the important thing is to be able to search by ingredient. There's a search engine, recipe puppy, that allows that, but it's a little unwieldy. You can also do it on epicurious.com. I have not been able to figure out how to do it on copy me that.