I suggest you learn Google's SketchUp.http://sketchup.google.com/intl/en/
It's 3D solid modeling and once you're used to designing in 3D you will never go back to a plain flat drafting package. It's a free download and all the features will work for 30 days. After 30 days some features quit, but for home use it's still very, very useful. There are lots of YouTube how to videos. If you come from a AutoCAD or other drafting package the drawing techniques will seem strange. But stick with it. Quite useful for building construction design. Current versions required Windows XP or newer. Version 6 will run on Win2K and is still available.
The paid version can import and export many standard drafting file formats. The latest versions also has a scripting programing language which can automate many tasks. Especially useful to create a parameterized library of part shapes. Does surface shading, look throughs, etc. Also has a "walk thru" function that can create a "movie like" automation.
For someone wants to improve their engineering/technical skills this is the program to learn. Just about all the features will work on the free download version. If I were an employer looking to hire a junior CAD operator and someone came to me knowing SketchUp well they would be hired in a minute. Even if my shop used a different CAD program.