Hello Pam
First to introduce ourselves, we are Rob and Stacey and we live in Yorkton Saskatchewan. From what we've gleaned from your posts it seems like you may be near us? If so then the area has many great resources growing these days. A local plant expert is Dr. James Jowsey who wrote the book Wildflowers across the Prairies. He live in Saltcoats and loves helping others identify and preserve local plants. There is also the Assiniboine Food Security Alliance which consists of many local gardeners, farmers, and other local producers(many organic)who share a wealth of knowledge about the area.
As to hosting the event, you can announce your event in a number of ways. The local papers, local websites, fliers at farmers markets, local groups(afsa, Hort. society) the list could be endless.
We recently attended a cob oven building workshop where the hosts supplied lunch and beverages. We were told a vegetarian lunch would be provided but it turned out to be beef on a bun with a number of salads. This we believe worked good as many of the participants were locals and appreciated both options. Food need not be fancy, sandwiches,salads or soups are quick to do and keep well enough. I hope this info is enough to get you started on growing your event, should be a great experience for all who attend. If you'd like to chat more with us feel free to send us a message. We too are planing on hosting a number of events over the coming years.
Rob and Stacey (GardenTherapyYorkton)