I recently stumbled across this link from the Cross-Linux From Scratch website, called
CBLFS (Community Driven Beyond Linux From Scratch)
http://cblfs.cross-lfs.org/index.php/Main_Page
Not all of the information is current and up-to-date, but it can give a generally good idea on how to install extra software into LFS, create boot scripts, and other interesting tid-bits, and could be a good source of information if needed on packages not normally covered by BLFS, LFS, or other scripted installs.
Hope you find it useful.