E-mail address is often the easiest way to find someone.

Then, just right-click on the contact and select "Add Contact"

added a friends cell phone but wouldnt accept it.

If you type the phone number and the contact doesn't come up, they're either not on Skype or don't have that phone number in their profile.

Either way, you can send them a link to your profile. Click on the icon for your profile (usually a circle with your initials in it, upper-left hand corner of Skype) and choose Invite Friends. Scroll down to Copy to clipboard and e-mail or text them that link. Or click Email which will start an e-mail with the link to your profile included which you can send them.

Once the profiles are linked (and they're on Skype), they should be able to call you for free.