First step would be to get the upgrade to 2.5 (which I believe is free).
Then, to get the most from it you’ll need to gain an appreciation for light and materials that differs from that you’d have had for DAZ Studio or Poser. With LuxRender being the render engine and Reality being the ‘translator’ what you have in your DS/Poser scene needs to converted into constructs that LuxRender understands.
Light, in LuxRender, is handled differently to DS and Poser, inasmuch as it is handled in a real world fashion. No need to use UE2 (in DS) to obtain ambient occlusion and overall lighting levels, LuxRender does that because it maps (as best it can) what light actually does. Thus if you have a light source it WILL cast shadows. The softness of those shadows will not be affected by a setting such as you get in DS, but by the relative closeness and size of the light source to the target.
Materials are also different. LuxRender endeavours to replicate real world behaviour of materials. Reality does a pretty good job in converting between DS/Poser and LuxRender but you will often need to step in and make tweaks. Main example if with the glossiness setting which often can stand to be reduced before starting the render - I suspect the term ‘glossiness’ has slightly different meanings in DS and in Reality/LuxRender! Changing material type wholesale can also work wonders - a useful trick is to change hair material from (probably) Glossy to Metal and then select the check box to make it a custom metal (as opposed to one of the in-built metal types like aluminium).
There are a wealth of hint and tips and so on on Paolo’s site