I laughed at your comment above about the z axis. When I used poser I could NEVER get used to the Y-axis being up and down.
bulbs: yes, select the bulb and in the general tab (upper right) you can reduce its size, brightness, AND have it invisible in the preview (scroll down to the bottom of the general tab page to reveal this check box).
The "infinite light that is on all the time" is one that took me months to find until I followed GKDantas' tutorial over at DAZ. Click on "scene" in the incidents tab. Then the general tab will show several categories for the environment of your scene, including "ambient". Open this and you will find a light with a slide bar, probably set at 20%. Set it to zero: your 3D preview will be very dark, but you will only have the regular lights in the render. 
A nice guide to building a scene, including advanced lighting options is GKDantas' "Tree with Fruits" tutorial over at DAZ. It takes you through a full scene construction.
Many people give up on the manual and go to VTC online tutorials for Mark Bremmer's C6 tutorial. (cost: $30 per month, online./ ~$90 for DVD)