Avoid copyright infringement lawsuits by not stealing other artists or professionals audio, video, or written material. The information or produced medias may be solicited as free online but in many cases the information is stolen illegally and attempted to be resold for a profit. Do a search for the content or piece before using it.
The best way to avoid copyright legal problems is by creating your own medias from scratch. Don't copy other work and you should be fine. If you do find yourself be prosecuted for taking credit for someones work you should assist the professional in removing the publication or if they allow you to just add in credit to the original producer of the material.
Avoid copyrighted content usage. You should not use a song you download and pay for from I tunes or other online music downloading sites to make videos or slide shows. Although many people do it online, technically the artist can sue you if they so choose.