Study Curve

AutoCAD is definitely one of the industry standards when it comes to rendering 2D and 3D technical drawings.

However, depending on what you want to draw and how precise you need to be, you might be interested in SketchUp (http://www.sketchup.com/). This software allows you to create, view and edit 3D models.

SketchUp is now part of the Google collection and they offer two versions. The main differences between the Pro and free versions is that the former allows you export your data to other software (ie AutoCAD, etc.) and create professional looking presentations.

It's definitely worth a look to see if it meets your needs. And, the price is right on the free version.

AutoCAD by Autodesk is considered the industry standard and used widely across many building disciplines and taught in most academic settings. Professional training is also available by independent manufacturer representatives and vendors directly. More vendors are entering the marketplace with varying degress of similarity, specialization and cost. A recent advance in the technology is Building Information Management (BIM). BIM employs technology to update multiple viewpoints; changes to drawings in one view and automatically are done withing the project (ie Floor plan changes are automatically updated in Elevations and schedule of materials). The best program is typically the one that is taught well. I would recommend interviewing professionals utilizing the technology and asking for their recommendation.

I am most familiar with AutoCAD. I find it relatively easy to use, though I have been told that other Cad programs are more straight forward. AutoCAD is fairly widely used in the architecture and construction fields, so for ease of portability, I would suggest AutoCAD by Autodesk.