I'm still learning HTTrack so you are warned :)

Well let's see the tutorials are at this url:

<http://www.blender.org/tutorials-help/tutorials/>

and by inspecting the element under TUTORIALS ARE SPLIT UP INTO THE FOLLOWING
CATEGORIES:
(I have Firebug in my Firefox and it's very handy for looking at HTML in
pages)

there's a bunch of List Item elements all with the HREF of:
tutorials-help/tutorials/#c

so maybe point WinHTTrack at <http://www.blender.org/tutorials-help/tutorials/>

then use the following filters and see what happens...

-* +*blender.org/tutorials-help/tutorials/#c*