If you are in doubt, call the company. Newer packages are being marketed for web use. To protect works that students or teachers publish online, put a copyright notice on it and register with the U.S. Copyright office. Registering does cost but will give you additional rights under the law. Any information used from the Internet in reports or presentations should be properly cited, just as they would be for any other source.
Several guides are available online to help with the correct format in citing Internet references.
Just because it is there does not mean that you can download it and use it freely. You should also check all downloaded files for viruses. Some of these are clearly marked as copyright protected and some are not. In some cases, even though the materials are copyright protected, permission is given to educators and students to use in the classroom for presentations and reports. Check the copyright of anything you get from the Internet before you use it on your web page or in the classroom.