Thanks!
I use SolidWorks 2006 and Rhino that cost $5,000 and $900 respectivly.
My suggestion would be to take a class at the local community college
and learn the difference before you invest the $1000 to $5000 or more
it takes to get a good package. Parametric modeling is the king right
now because it is easier to make updates.
If you want to get your feet wet buy a low cost package and plod
through it. You will quickly know what you don't like and what you do
like.
Visit www.ThinkSolveDo.com and read their CAD article! It has some
links to free software that you can download and begin using right
away. Make sure the CAD package you get can export and import IGES
files. This will allow you to make your work useable in many different
packages. So if you switch you are not stuck! You might also want to
get a cheap PC to use some of the low cost CAD programs that are easy
to get.