The process of creating a booklet is called imposition. It is usually best done after the fact on a PDF file. There are a number of utilities that can create booklets from PDFs (as a bonus the tools aren't specific to FrameMaker) or they act as printer drivers do this during the output stage to PDF.
Some of the PDF-based tools out there for this include:
Quite Imposing at http://www.quite.com
PDFSnake at http://www.pdfsnake.com
cutePDF at http://www.cutepdf.com/
PDFenhancer at http://www.apago.com/pdfe_imposition.html
CheapImpostor at http://www.cheapimpostor.com/
dots Pilot 2 http://www.dots-software.com/pilot.php
There are some printer drivers that will create booklets. However, they all do not support PostScript in most cases, so if you have EPS or PDF graphics, you shouldn't use them.
FinePrint at http://www.fineprint.com/products/fineprint/index.html
ClickBook at http://www.bluesquirrel.com/clickbook/
CMYK PDF Creator (supports postscript and provides colour correction from FM) from Grafikhuset at
Finally, there used to be a plug-in for FM available from Mekon called mPose (or something like that), but it seems to have disappeared from their website. See http://www.mekon.com