Olitek have found some useful reference resources over the years, we thought you might find a few useful. 

www.edrawingsviewer.com - Free CAD viewing tool for 2D drawings and 3D models

www.joshmadison.com/software/convert-for-windows/ - Useful Convertor for Engineers

www.solidworks.com.au - Supplier of SolidWorks® 3D CAD

www.adacad.com - Supplier of Autodesk Inventor® 3D CAD

www.leapaust.com.au - Supplier of ProEngineer® 3D CAD and Ansys® FEA Software

www.miningaustralia.com.au - Update yourself with mining information

www.matweb.com  - A source for Engineering Materials data