Professions Icon Set (34 Icons, PNG),The set contains 34 icons for various occasions. The Icons are available in eight sizes — 32×32 px, 48×48 px, 64×64 px , 72×72 px, 96×96 px, 128×128 px, 256×256 px, 512×512 px.
The icons are licensed under the Creative Commons Attribution 3.0 License. You are free to distribute, transform, fiddle with and build them into your work, even commercially. You can use this icon set freely for commercial and personal projects.