There are many html files in the system. You could read them with text base web browser. There are elinks and lynx. The elinks has more functions.
You could move forward with ctrl-f, back with ctrl-b.
$ elinks /usr/share/doc/centos-release-4/RELEASE-NOTES-en.html
$ lynx /usr/share/doc/centos-release-4/RELEASE-NOTES-en.html
Many Linux distributions has file name with release in /etc.
$ ls /etc/*-release
/etc/redhat-release
If you open the file, it tells you a version of the distribution.
$ cat /etc/redhat-release
CentOS release 4.6 (Final)
uname command shows your system information.
$ uname -a
Linux myserver.example.com 2.6.9-61.EL #1 Wed May 2 13:50:59 EDT 2007 i686 i686 i386 GNU/Linux
if you use -m option, it only shows your CPU architecture.
$ uname -m
i686
