In addition to providing high-resolution output, many service bureaus also offer scanning services, as well as general consultancy. Some service bureaus have computers equipped with desktop publishing software which you can rent by the hour.

Approved imagesetting bureaus 
Serif's list of approved imagesetting bureaus.

Linotronic service bureau
The Linotronic Service Bureau site provides information on their electronic publishing services, along with links to popular Macintosh and PC software, as well as a wide range of scanning and imaging devices.

PrePRESS Main Street site
Provides a collection of links to electronic prepress inforrmation including how to's and tips, reference material, trade shows listings , and an extensive list of prepress products.

PrinterNet - Directory of printing services
Contains a directory of commercial, publication, packaging and specialty printers.