That depends on what they're in on the PC - a text file, a spreadsneet, some personal address book program, Outlook Express - the best and easiest way is different for each one. Uploading a csv file of them to Google Contacts would probably be the easiest way - if you can generate a csv file in the right format. (Put in one contact at the site with as many fields as you can fill in, then export it as a csv file. Look at the file in Notepad (with Wordwrap off) or Excel and you'll see the format that's needed.)