Having just come off the big push for "Bike-to-Work Week" and a couple of workshops supporting that, here's some references that I've found useful... One of the best little handbooks I've found for working this at the employer end is from the San Francisco Bicycle Coalition, with a lot of input from the Bicycle Federation of Wisconsin:
http://www.sfbike.org/?employers
http://www.bfw.org/articles/bikecommuting.php

And BFW's "Parking For Free" employer's guide and case studies:
http://www.bfw.org/projects/commute.pdf

From the Bicycle Coalition of Maine:
http://www.bikemaine.org/btwemployer.htm

And from BikeIowa:
http://www.bikeiowa.com/asp/bike/EmployerGuide.asp

Lots of good stuff from the San Francisco Transportation Management Association:
http://www.sacramento-tma.org/Bicycling.htm

Some facts and figures from Commuter Connections:
http://www.mwcog.org/commuter/Bdy-bike10.html

And from RoadBikeRider.com, this is one of the best little handbooks that's currently out there... I've had a copy for awhile (and use it heavily in the LAB Commuting course), but they were giving it away last week at least...
http://www.roadbikerider.com/bc_excerpt.htm

We used the San Francisco handbook as a basic for a locally tailored employers guide for central Arkansas, and will continue to refine the package for use over the summer and in future BTW campaigns.

Hope this helps...

Tom
LCI #1853
Bicycle Advocacy of Central Arkansas
Education committee