Step 1
Find two or three people who are well respected by the business community and who are willing to be active in the organization.

Step 2
Create a business Plan.
It is important to have this well thought out before making a formal presentation lest people see it as little more than "increasing taxes". I think most business can easily see the value of "promoting" Woodstock. Especially those businesses in the center village area. Much less clear is whether we can create methods of attracting visitors to the perimeter business by various, promotions, events and circling busses and thus convince those business to support creating a BID.
Once we have a well thought out business plan, we should focus on getting support from perimeter business first. This done, getting support from center village businesses should be comparatively easy. (Ultimately, for the referendum, we need support from 51% within the existing commercial district).

More ideas...
LINKS FROM THE ASSOCIATION OF TOWNS--

Town BIDs

The Arlington District of Poughkeepsie, The Arlington BID is comprised of a group of small business owners, residents, schools and other interested parties located in and around the Arlington District. The primary purpose of the BID is to establish, promote and realize a vision for revitalization, enhancing the community life of the area, the tourist and economic potential of the district, and the general atmosphere of the streets.

Town of Dewitt Business Improvement District (BID)

City BIDs

Downtown Albany Business Improvement District (BID)

City of Norwich, Chenango County
The Norwich BID was formed in 1986 by the City of Norwich to help preserve and enhance downtown Norwich. It was one of the first BID’s in New York State. In 1992 the Norwich BID was incorporated as the Norwich Business Improvement District Management Association, Inc. (BIDMA, Inc.). Their goal is to continually improve upon our downtown and its offerings.
From NYC:

STARTING A BUSINESS IMPROVEMENT DISTRICT A STEP-BY-STEP GUIDE in NYC
Business Improvement Districts have been important partners in the economic development of New
York City for more than 20 years. From the central business districts to local shopping areas, BIDs
make valuable contributions to the life of our neighborhoods. Establishing a new BID is a serious
effort that involves the work of local businesses, public officials and other community stakeholders.

A different idea that includes both Business & Residents:
The Nantucket Civic League

The mission of the Nantucket Civic League, founded in 1903 and representing 22 neighborhood associations and over 1800 dues-paying families, is to promote the general welfare of Nantucket through informed citizen participation in community affairs.....

Something that would be helpful is if we had more links to towns about the same size of Woodstock that have sucessful B.I.D.s.