geez, sounds like you have a lot of books!! my first thought was EBAY! is there any that you could live without?? could you and DH have like a 'day' to sort through books and keep ONLY what will fit in your 3 bookcases?? just an idea!

as for the rest of the clutter, i reckon if storage is the way to go for you, then go for it! like others have said, you may find you can throw out a lot of stuff and not have quite a smuch as you had first thought! i agree with uniform tubs/boxes for stacking. nice big labels and maybe even a list as to what is in each tub- keep a copy at home. depends how organised you are i guess.. im a bit OCD when it comes to storage!

i hope you feel better after a de-clutter!