It is permitted to copy or scan a few copies of a published work (for example, a book or journal) for personal use like for studying and hobbies. Personal use means family and closest friends. The copy cannot be used for other purposes later.
All material found online is not automatically free to use. If you, for example, add a photo to your home page, no one can copy or use it without your permission. However, it is permitted to link to free online materials.
1. Contact the creator and ask for permission
2. Search for open Creative Commons (CC) licensed material here: http://search.creativecommons.org/
Photo: Student by CollegeDegrees360 (CC BY-SA 2.0)
A student has copyright to her or his own material, such as a thesis. Students must give permission to save their work to the Internet or the university's intranet.