Most of the coreutils documentation is available as info pages. (Try "info
coreutils" at a command prompt). A version of this documentation is also
available online at
http://www.gnu.org/software/coreutils/manual/html_node/index.html
(Note that the online version may not reflect the version of coreutils in this
package.)

There is also a frequently asked questions document available at
http://www.gnu.org/software/coreutils/faq/coreutils-faq.html