Many works available on the internet may offer low cost or bundled licenses for doing what you want.
Read the label-- especially if you are considering buying clip art! Make sure the license covers the use you need--
The Copyright Clearance Center sells licenses for copyrighted works whose owners have contracted with them.
Your organization may have an academic license with them.
Even if they do not, you can use the Copyright Clearance Center's website to find out how much it would cost to license the rights.
Creative Commons licenses allow creators to define uses & conditions under which their works may be used. These are often uses that are normally protected by copyright, but in these cases are allowable. For example, if you see this license
it means you are allowed to use, remix and build upon this work as long as your use is noncommerical and acknowledges the creator.
Open Access content is peer-reviewed scholarship available at not cost to the user. One place to search for open access journal articles is in the Directory of Open Access Journals (DOAJ).
Questions? Need Help? Email firstname.lastname@example.org
Drew University Library, http://www.drew.edu/library