Unit Studies are fun but the volume of craft supplies and books can be overwhelming to manage. 

I try to make a complete list of needs before we start each unit.  The list has 4-10 weeks worth of crafts supplies and library books that we will use.  Then I make one trip to the craft store and one trip to the library to gather everything...  but then what?  I have a ton of stuff that gets misplaced or used before we even get to our studies.

To keep from losing my mind as I lose the library books, I sort everything into weekly boxes.  I bought 10 of the boxes at the office supply store that always go on sale at tax time and labeled them 1-10.  When I get home from our shopping spree, I immediately store everything in the appropriate box.  Week 1 stuff goes into Box 1 and so on.  Then I put the lids on the boxes and store them stacked in our school area.  After we complete the projects in Box 1, we move on to Box 2 which has everything that we need for the next week.  I also have a list of contents attached to the outside of each box.  I highlight the items that need to be advanced to a different box when we are done with them.