I don’t think you’ll face any serious problems using Windows, though I do all my design work on the Mac side. The biggest issue will be fonts, and that’s gotten a lot easier with fonts that work on both platforms. But an old book done on the Mac will call fonts that you don’t have on the PC and can’t really install. You’ll have to change to a different font. Good side of doing that for a book: you probably only have to worry about two font families. Bad side: you might find that changing fonts or programs causes all 300 pages to reflow.
Adobe has been doing a big push for the last 5-6 years (since they renamed it “Creative Suite”) to make their products work identically whether run on Mac or Windows. That’s not to say there’s no practical difference, but Adobe has been working hard for many versions now to remove any practical differences.
The only thing I can think of off the top of my head is font rendering… Macs smooth fonts using a very different algorithm than Windows, but I’m guessing that even if the fonts looked different on-screen they’d come out identical on the printer.