Hi Sara - I had to completely pack up my library a couple of years ago. My best advice is make sure you have a strategy for packing up the books so that they stay organized. If you will have helpers, I would suggest teaching them how you want everything packed. Clearly label all of your boxes or bins and consider a numbering system so you can put the boxes in order before you start unpacking. I would also start weeding now and continue weeding as you pack. Decide ahead of time where your weeded resources will go (books, old DVDs, maps, etc.). I gave away a lot of books to my students, libraries in underserved communities, Goodwill, and Savers. Clearly there were some things that just needed to be trashed as well. Also, if you know what the new space will look like and what kind of shelf space you will have, it also helps to map out a floor plan so when you're ready to unpack  you already know where everything is going to go. And take some before pictures! It was great fun to look back at the differences. Best wishes for a smooth move and I hope you get to be there to enjoy the move back into the new space as well!