If you are working on Zero Textbook Cost Degree (ZTC) planning you may be able to get a list of textbooks used in a program from the Campus Bookstore. These lists can help you know what is being ordered and used in a program and what needs to be replaced. You can also usually look up titles being used by course number on Bookstore websites.
Having buy-in from Senior Administrators can be helpful in smoothing communication with the Campus Bookstore. Sometimes campus-wide OER committees also have Campus Bookstore membership, so the Bookstore can be included in decision-making and be included in campus-wide OER and ZTC Degree planning and communication about institutional priorities. For example University of Calgary has bookstore representation on their OER Committee.
Print on Demand Services for OER Textbooks
Most OER textbooks come in electronic format, and can be made freely available via a web link or in PDF format to students for example. However, sometimes a student prefers to have a print copy of a textbook for various reasons, even if they have to pay printing costs for the paper version. One way for Campus Bookstores to be involved in an OER program is to assist with offering print-on-demand services for students. Students then pay for the print costs of producing the textbook but this is a fraction of the cost of a traditional commercial textbook. Kwantlen Polytechnic University has worked with the Bookstore to provide OER print on demand services for instructors and has set up a handy guide to show faculty how to order print on demand copies. 
Copyright Considerations for Printing Zero Textbook Cost Degree Materials
Sometimes the Bookstore that serves your Campus is an independent Bookstore. In that case you still may want to build and investigate relationships with the store, but they may not be possible depending on the stores governance.
- Zach. R. (n.d.). How to Get (Printed) Open Textbooks to Your Students http://openlogicproject.org/2016/09/12/how-to-get-printed-open-textbooks-to-your-students/ ↵
- Jhangiani, R. (n.d.) Print on demand setup tutorial. Kwantlan Polytechnic University Retrieved from https://media.kpu.ca/media/Print+on+demand+setup+tutorial/0_izv6teqn Licenced CC BY 4.0 ↵