If you are after an easy to use 2D CAD program for Windows / Linux. Try QCAD from http://www.ribbonsoft.com. Currently at version 2.2.x but a newer version QCAD 3 is in release candidate phase.

At under 100$ AUD for a license it's good value. And with modest CAD skills you can do useful stuff with it. For example my front fence:

front_fence

QCAD 3
I have been using the QCAD 3 release candidate.