LDP is a loosely knit team of volunteers who provide documentation for many aspects of Linux. There are several forms of documentation: Guides, HOWTOs, man pages, and FAQs.
You can browse it at
http://tldp.org/
Two years back I bought it on a cd for a small fee. This can be used for offline browsing of the LDP. I have posted it here:
part1 Size 99 MB md5sum 566ead529b4dda2a5e1c84f450670508
part2 Size 99 MB md5sum f02e0a56dc62a8b14515311d599ce35b
part3 Size 99 MB md5sum 8c6952ca86e41f6a8d1dcf58b9810f89
part4 Size 27.8 MB md5sum 3442d552fd1b35e1e6ba17086ed6581c
Archive type: 7z, spanned, using
Peazip
The Linux Documentation Project
Linear Mode
