I'm often asked what software I use, and am probably long overdue at sharing this post. I'm answering this question from the perspective of my primary job - Production Designer at Kensington Church. *See below for more context if you're interested.
I'm a fan of OmniGraffle (Mac or Microsoft Visio if on PC) It's great as a basic 2D CAD with layers and everything; and its drag and drop simplicity of putting icons for people and set pieces into place is pretty fantastic.
The price point is also great, especially for multiple users.
Vectorworks is awesome, but is more (both in cost and complexity) than our workflow requires - especially with multiple users; most of whom are not "designing" but rather just laying out a plot.
There are many other programs I might consider writing about, but I'll leave this post with the above two mentions for now. Connect with me and I can share my workflow if you're interested…
*I design for our main broadcast location. We have 4 other campuses each with a TD who is responsible for figuring out how to take the central designed service and make it work on their stage, with their team and resources, and with whatever might uniquely happen at their campus that weekend. We move fast. At our location, we have at least 2 completely different stage designs every week…see: http://egwolfe.tumblr.com/post/6144545367/we-change-our-stage-with-a-completely-unique