You'll want to make sure 'links' is intalled in the right place. I recommend /usr/local/bin simply because by default this is part of your default path. Any time you install a new binary you'll want to type rehash to get the shell to see it in your path. You can see your current executable path by typing env | grep PATH or set | grep path (case-sensitive!). Look for /usr/local/bin.
Do you know where your copy of 'links' was installed? The version I'm providing always puts things into /usr/local/bin but you can find out where your install went using sudo find /usr -name links and entering your admin password.
The correct way to view any man page is to enter man <topic>