Market research reports are incredibly expensive, and the libraries don't have the budget resources to purchase individual reports for each student business plan. You can find some full-text reports via Business Source Complete and Factiva.
Otherwise, utilize the secondary data about consumer behavior available through Mintel Academic.
Data on U.S. consumer attitudes & preferences. All sites can be searched free but full reports are not always freely available.
These resources give you insight into demographics, market areas and consumers' tastes and preferences.