IIRC the Boot Camp installer blats a read-only HFS+ driver into Windows, so you can read the files from whichever is the non-booted OS -- but if you need to work on the same thing in both OS's you have to keep the data external or have 2 copies and check which is the latest.
Apparently it doesn't work on Mac mini's with RAID'd drives, and I read that there are issues with reading the Mac partition from Windows if the Mac has a Fusion Drive (though Boot Camp works otherwise).
At work we use Parallels, which is much much better (though it costs actual money, so would need to be).
Desktop: E3-1270 v5, X11SAT-F, 32GB, RX Vega 56, 500GB Crucial P1, 2TB Ultrastar, Xonar DGX, XL2730Z + G2420HDB
HTPC: i5-2500K, DH67GD, 6GB, RX 580, 250GB MX500, 1.5TB Barracuda