I apologize in advance if these tips are obvious but they are tricks that really helped me when I figured them out.
PRINT BOOKLET (file -- print booklet)
If you're printing a book, there is no easier way to print it than this. Trying to reorder your pages to print in order will have you pulling your hair out.
***There is a glitch in CS6 with Print Booklet. If you have changed the size of your document at any point while designing, you will get the below error message. It doesn't make sense but it will not print. The work around is to paste all of your pages in a fresh document that has not had the document size changed. This is when PASTE IN PLACE becomes your best friend. Just select an entire spread -- copy -- click on page in new doc -- paste in place. When I first went to print a booklet last semester I literally took hours (and possibly some tears) trying to figure out this error message and why it wouldn't print. I'm sure some of you have had a similar experience with this glitch.
DUPLICATE SPREAD (select page/spread in pages panel -- right click -- duplicate spread)
I work on multiple versions of a design within the same document. I used to copy a page and paste it on a new page to duplicate. When I did this, everything pasted to a single layer. Duplicate spread maintains your original layer organization. It took me a while to realize this and life became easier when I did.