I assume you understand the programming?
Ringing is assigned in MMC 406.You can assign either a direct extension or a group.You must use a group if you want more than 1 phone to ring.If you do this then you must assign the group in MMC 601.Just make sure if you do this to set the ring type to unconditional and include all the extensions that you want to ring as members of the group.
For key programming use MMC 722.This is on a per station basis.
If all the phones are the same then you could use MMC723 for system key programming.
Or you can program 1 phone and use MMC720 to copy the key programming from 1 phone to another.
Direct trunk keys are DT7XX.Example a key code for a line 1 button would be DT701.