Shaun, I am yet to find the 3D package that really meets my needs for plans to submit to the building department, and also visualizes the project with a 3-D walk-through or fly-over. The one that comes closest in my opinion right now is Punch Home Design Architectural Series. http://www.punchsoftware.com/index.htm The program is fun, but time consuming. It can be difficult to get things lined up especially in complex split level or sloped plans. This is probably your best bet on consumer level home design that lets you change colors, floor plans, landscaping, decks and even do virtual makeovers on digital photos. Fun package.
For precision layout and elevation plans and the details required by permitting, I still rely on Autocad 2000 and have found that Microsoft Visio also does great 2D scale plans and site plans. Forget about Autocad unless you use it professionally, but Visio is a possibility that might fit your needs depending on what you do.