Here's a DOS 3.3 System Master disk. It's really easy to see that the "Boot Blocks" take up three whole tracks, and the Volume Bitmap is at track $11, sector $0, and the VTOC (Volume Table Of Contents) occupies the rest of track $11. Interestingly, you can see how files are allocated on a DOS disk, they go one per track, starting at sector $F and working their way down, so there are lots of extent blocks at sector $F. You may recognize the track and sector labels from Copy ][+, of which I am a fan.