To work with us, you'll need to first register as a county vendor. Click here to visit the Riverside County Purchasing and Fleet Department.I have read the Volunteer Services Agreement and confirm that has my permission to participate as a volunteer in the program described for the. Region. (Date). Requests for Proposals, Negotiated Acquisitions, Competitive Sealed Bids, Notice of Renewals, Request for Expressions of Interest, NYC Procurement Roadmap Riverside City College. 4800 Magnolia Ave Riverside,. "Covered Professional Services" as designated in the policy must specifically include work performed under this Agreement. Riverside County Codes. Service to provide: RIVERSIDE COUNTY SUPPORTIVE COMMUNITY SERVICES. To set up as a new vendor, please sign up through the sign-up link and download and fill out the Vendor Agreement form, which can be downloaded below.