How would I print a report with the names and email addresses of all the contacts who have a certain user field?

Ann,

You need to perform a seach on the user defined field in question with the value you want set as the search criteria. This will return a list of all records that have that field with the specific value.

Then you need to create a column layout showing Name & E-mail address and use it, then all you need to do is click File>>Print>>Column Report.

Thanks very much. That was great.