I'm interested in learning how to "roll calls","screen calls", make "conference calls", "international calls", and any other additional information I should know for office phone skills. Please tell me step by step on how to do this and what features on the phone to use. In detail explain each step and where to find the feature on the phone like a 101 class. Websites and book recommendations is okay, but I prefer for someone to tell me in detail how to do this. I have very minimal skills using office phones and I'm interested in improving. Thank you! 