Let's create the directory tree on the LFS partition based on the FHS standard, which can be found at http://www.pathname.com/fhs/. Issuing the following commands will create a default directory layout:
mkdir -p bin boot dev/pts etc/opt home lib mnt proc root sbin tmp var opt
for dirname in $LFS/usr $LFS/usr/local
mkdir bin etc include lib sbin share src var
ln -s share/man man
ln -s share/doc doc
ln -s share/info info
mkdir dict doc info locale man nls misc terminfo zoneinfo
mkdir -p lock log mail run spool tmp opt cache lib/misc local
mkdir bin doc include info lib man
ln -s ../var/tmp tmp
Normally, directories are created with permission mode 755, which isn't desired for all directories. The first change is a mode 0750 for the $LFS/root directory. This is to make sure that not just everybody can enter the /root directory (the same a user would do with /home/username directories). The second change is a mode 1777 for the tmp directories. This way, any user can write data to the /tmp or /var/tmp directory but cannot remove another user's files (the latter is caused by the so-called "sticky bit" - bit 1 of the 1777 bit mask).
cd $LFS &&
chmod 0750 root &&
chmod 1777 tmp var/tmp
Now that the directories are created, copy the source files that were downloaded in chapter 3 to some subdirectory under $LFS/usr/src (you will need to create the desired directory yourself).
The FHS stipulates that the /usr/local directory should contain the bin, games, include, lib, man, sbin, and share subdirectories. You can alter your /usr/local directory yourself if you want your system to be FHS-compliant.
Also, the standard says that there should exist a /usr/share/games directory, which we don't much like for a base system. But feel free to make your system FHS-compliant if you wish. The FHS isn't precise as to the structure of the /usr/local/share subdirectories, so we took the liberty of creating the directories that we felt needed.