Hello and Welcome to LinuxQuestions,
Here are some links to sites that list most (if not all) general Linux commands. Whether you can use them in ALL Linux distros depends on the distro if they come installed per default. For example chkconfig which is typical for RPM based distros is not per default installed in Debian based distros but can be installed through the package manager.
http://www.oreillynet.com/linux/cmd/
http://www.linuxcommand.org/superman_pages.php
http://linuxmanpages.com/
Looking forward to your participation in the forums. Have fun with Linux.
Kind regards,
Eric