does anyone know of some free software that can add sound effects to my blender animations?
Also checkout the freesound project, lots of sound effects there
and you can get good music and mixes, also creative commons licence from ccMixter
Watch out for the CC licence as anything created is therefore subject to the same license. So if you use other people’s models…they may not be compatitble with CC. As a general rule, I tend to avoid CC for video/audio projects because there can be problems.