I’ve gotten more into marking up the books I read, with lots of underlining and notes in the margins. This can be unkind to people to whom I want to lend or give the book – though sometimes (not always!) I enjoy reading other people’s comments when I buy a used book.
My friend Jim Forest introduced me to a nice way to take notes without messing up a book for others, or for one’s self when re-reading: he puts all his notes in the endpages of the book, like a personal index. Here’s an example:
Right now I’m re-reading a very nice hardcover of The Lord of the Rings that we were given years ago. I like keeping the pages pristine, but this time I want to be able easily to look up some favorite passages (do you know where to find “The world is changing…”?). Endpage notes will not only keep the book clean but will make it much easier to look up such things.
An alternative, I guess, is to keep a separate notebook or commonplace book for quotes and thoughts. It has its own advantages, but I prefer to have my notes right at hand when reading in bed, the tub, etc. This will, I think, be my new method.