In hopes of making it a little less intimidating though, here's some tips for handling phones on the job:
Try to learn how to use the phones at your office as quickly as possible and get comfortable with it. You don't want to accidentally hang up on someone when you're trying to answer a call or, even worse, accidentally transfer an obnoxious guy calling to tell you that he's the next big thing, when you're trying to put him on hold. Actually knowing how to use the phone system will make you feel less nervous and it's generally pretty essential anyway.
Sounds obvious right? As a general rule, you should never let a phone just keep ringing (if you have the authority to answer it that is). Learn what lines you should cover and be sure to get any call that comes through or that your boss can't get (if you're supposed to act as back up for his or her line).
Whether you're just transferring the call immediately or actually taking a message, you should take a few notes anyway just to keep a record of who you talked to and what it was about. Then, if your boss can't remember and asks you who she was supposed to call back, you'll actually know. Every time you talk to someone you should get their name, where they are calling from, and what the call is regarding. If you're taking a message you should also be sure the person the message is for has their contact info.
Learn Your Office Etiquette
Every office has different rules and different levels of formality for incoming phone calls. Learn yours and follow them. This may mean not leaving the desk if someone else isn't there to cover the phone, it may mean automatically telling certain people that your boss is in a meeting, and it may mean using a certain method to communicate messages and who is on the phone. Whatever it may be, make sure you know it and adhere to it.
More tips to come!