Filesystem

/ - the root home
/bin - all executables
/sbin -> /bin # softlink pointing to /bin
/boot - all boot files
/etc - system configuration
/home - user directories
/var - spool, run, log, cache
/share - man pages, locales, dependencies
/include - include/headers
/lib - static libraries for building stuff
/mnt - mount points
/usr -> / # softlink pointing to /

Based on the Linux assumption:

/dev - devices
/proc - proc files
/sys - sys files

For crap stuff:

/sucks - stuff that sucks, like ugly gnu library dependencies, or systemd fake handlers