In addition to collecting contact information, a registration form helps you focus your material to the interests and experience level of your student(s). Try something like this:

• What course are you interested in?
  (or: What program/skill would you like to learn?)
• Are you doing this for work, school, or personal interest?
• How long have you been using computers?
• Do you have a computer at home? What operating system?
• What do you use computers for?
  (or: Which of the following have you done before?
  • email
  • chat or instant messaging
  • internet research
  • word processing
  • editing/printing pictures
  • troubleshooting
  • basic system maintenance
  • installing software
  • installing hardware
  • other: )

Finally, get their name and number (in case you have to cancel), and make sure you're both clear on where, when and for how long you'll be meeting.

When registering people over the phone, especially for one on one sessions, read between the lines. What happens when you use a term they don't understand - do they ask right away what you're talking about, or stay quiet until you realize they're confused? Are they self-conscious or matter-of-fact about needing training? Are they businesslike or sociable?