Number of pages must be a multiple of 4 (Add up to 3 blank pages.)

Page Layout → Margins:

• Multiple Pages → Book Fold
• Optionally add Gutter

CTRL + P:

• Select "Print On Both Sides" if you have a duplex-capable printer
• Or just use "Manually Print On Both Sides"

Test with 8 or 12 pages before printing your 200-page book.

I recently printed my first, 100 pages long, coil bound, paperback book and it took me a long while to wrap my head around how simple it really was to do.
Trust your software to work logically. Trust your printer to do it right.
Just thought I'd share what I managed to figure out.

Useful tips:
A big book is not better than a small one. Most great books are under 100 pages. (Mine was over 200 pages, but I cut it down to 100.)
Don't artificially inflate your book's size by increasing font size, doubling line spacing, adding extra-wide margins, messing with letter and word spacing.

I used 12pt Palatino Linotype for text, 16pt Helvetica for H2 titles and 14pt Helvetica for H3 titles.