I believe in notebooks. They can be journaling books, binders, fancy notebooks from the bookstore or office supply place, small note pads or whatever you like. Some should be small enough to keep beside you when you are reading and writing. Binders can hold information you’ve printed out from on-line or pulled from magazines.
Each one should have its own purpose. One for reading. One for writing. One for marketing. One for your recipes, etc. You might have one for each book you write with research, lists, notes, anything to do with that book.
But most important for a writer is to have one for reading and one for writing.
Why for reading? Because as you read, you should note down anything you find interesting or important. You might even have one for fiction and one for non-fiction. For example, for fiction, put down the date you read it, title, author, perhaps year it was published and by whom. Write down the main characters’ names, quote lines you liked, and when you’re finished reading, write down a quick plot summary. Note whether you liked the book or not, maybe even giving it a star rating. After you’ve done this for about a year, you can see what you liked most in plots, characters, and the writing itself if you’ve written down great lines. This will help you with your own writing and to pick out future reading. For non-fiction, simply fill in the title/author/etc., then jot down every highlight—the things you find most interesting and want to remember. Of course, if you own the book, you can also simply mark it up and put it in your bookshelves. Perhaps even dedicate shelves to those books you have marked up.
For writing? Every time you read a great article or book, be sure to write down the important things, things that you think you need to remember or need to keep in mind when you write. You’ll find yourself reading over this notebook every so often. I recommend you do so before you start writing each novel. You can also mark up these books you own, too, of course.
Notes and notebooks are your friends.