In The Life-Changing Magic of Not Giving a F ck, "anti-guru" Sarah Knight introduced readers to the joys of mental decluttering. You'll discover Praise for Sarah Knight. You need to Get Your Sh t Together.
The Life-Changing Magic of Tidying Up by Marie "KonMari" Kondo - HARDCOVER
Probably the MOST POPULAR book on solving your clutter problems available right now. You'll find some incredibly neat tricks (t-shirt folding!) and surprising insights about your stuff and your space. I love it, I reckon you will, too.