How do I submit a bid or proposal? All formal bids and proposals shall be submitted as specified in the solicitation document.Below are links to solicitations available through Maricopa County. Open Book to be used with general contractors bidding out multiple subcontractors. General contractors should use this method of pricing. For design-build construction services and job-order-contracting construction services, the Request for Proposals shall include: 1. The Maricopa Association of Governments (MAG) is requesting proposals from qualified consultants for the. Complete and return the attached City of Maricopa Substitute W9 form.