Medhue, of Medhue Animations, has a tutorial video up on weight painting for Second Life using Blender 2.71. The information in general works for any modeling system. But, is specifically for Second Life and Blender w/AvaStar users. While the ideas are transferable to any system, the button presses are specific to AvaStar users. He does not get into Fitted mesh, but for a button press or two it is the same.
There is a commercial in the middle if you watch on YouTube. Its short but it is a surprising burst of sound.
This tutorial is based on Medhue’s work flow, which is very much like the workflow pattern I use. The basic idea is to make one master weight garment or body and then use that for all future weighting. Medhue shows how to do that.
You can discuss the video with Medhue in the SL Forum here: Tutorial – Rigging & Weighting in Blender 2.71 with Avastar for Second Life. (I modified the title a bit…)