My books are very important to me. So needless to say, this will be one of the most difficult and largest categories for me. Here is an excellent example of decluttering a difficult category. I share how I work through the emotional attachments in hopes that it will help you to learn to how to examine and overcome your own emotional hurdles on this decluttering journey.
The Craft Box Project
The Simple Living Box Project
There are many different philosophies that are used as tools to help you on your minimalism journey. I have created my own process that helps you declutter efficiently without any regrets (and those two things do not usually go hand in hand). Make sure you apply this method to take full advantage of the "Purgatory Box" philosophy as well.
The Purgatory Box
Decluttering can be overwhelming at times so it is a good idea to make sure that you have a safety net so you don't make any hasty decisions that you will later regret. The "Purgatory Box" system is designed so that you don't get rid of anything that you are not ready to part with yet. Go take a look. It could save you a lot of heartache that would have been easily avoidable.