A Click the Directory tab and click the link See friends who are already on Skype. You'll see an Add contacts screen.
Under Check your email contacts, click in the checkbox(es) beside the email accounts you have.
If you have a Yahoo account, type in your username and password then click Search email contacts.
Skype uses your Yahoo login to check if your contacts are on Skype – it never saves it, ever.
Wait for Skype to search your contacts.
If Skype finds a match, it will list the friends who also use Skype.
Click in the checkbox beside the people you want to talk to on Skype.
Then click Add contact.
Write an introduction message so they know who you are.
Click OK to send. Depending on their security, you can IM them. When they accept your invitation, you will be able to see when they are online and call them, too.
Add a specific person:
Click the Directory tab and go to Find people.
Click in the box and type in their name, email address or Skype Name.
Click Search. Wait for Skype to search.
In the list, find the person you're looking for. Check details like location and click this icon 
to double check it's them.
Click on them, then click Add contact. This will open a Say hello window.
Click in the message box and type an introduction message so they know who you are.
Click OK to send. When they accept your invitation, you will be able to see when they are online and call them, too.
Add a phone or cell phone number: Click New and choose New Contact.
Find the link Save a phone number in your contact list.
Click on it. This opens an Add a contact window.
In this window, enter the person's name, select Home, Office, Cell phone or the other options from the dropdown list, then click on the flag to choose the country they are in.
Click in the box beside the flag and type in the phone number.
Check it. If it's correct, click Save phone number.
This saves the number in your Contact list.
is on Skype so it's free to call. Anyone with one of these 
means it's a phone or mobile number and calls will cost you a little.) 
to mute your microphone so the other person can't hear you.
to put the call on hold.
to add more people to the conversation.
to save the group in your contacts. When you need to pick up the conversation again, just click on the group instead of adding everyone in all over again.
