I used to work in the book business (for any Vancouverites out there: Duthie's on Robson & UBC Bookstore.) Books were seductive and I accumulated a lot of them. At Duthie's I had a charge account and a discount, and when I left I was a couple of grand in the hole. At the UBC Bookstore, I limited myself to mostly borrowing books--you could sign them out to read them 'gently.' I eventually made a rule for myself that I would not buy a book unless I was going to start reading it that day. I have stuck to it, for the most part. Now I have a mortgage so it is easier to not buy a book. I have been getting great mileage out of all the free books available for the Kindle and enjoying classic reads. I also use the local library; it has a great, online reserve and hold system. Probably 20-plus years in AA has helped me with my resolve as well--lots of things that used to be unmanageable are no longer a problem.
So, my advice to all you bookaholics out there:
If you have a book underway, finish it before you buy another.
Use the library.
Catch up on the classics--for free!
Only buy a book you are actually going to read that same day.
Good luck and remember one day, er, book, at a time.