Nonprofits all must file a Form 990 with the IRS, even though they don't file taxes. Use Guidestar (create free account) to look up the organization's basic profile and view several years of its 990s
NOTE: Some organizations' legal names don't match their public-facing names! For example, Bishop Arts Theatre Center is legally Teco Theatrical Productions.
Research the industry of your organization (for example, live theater) as well as nearby competitors (for example, music performances or live comedy shows).
Information here helps to create your SWOT or PESTLE analysis, because it shows the bigger issues affecting the whole industry, not just your organization.
Arts-specific data, marketing information, case studies
Statistics & studies gathered by market researchers, trade organizations, scientific publications, etc
Read some articles here both about your organization, the industry, and consumers: