l.4 --- TeX4ht warning --- \Configure{...}? ---
! LaTeX Error: Missing \begin{document}.
Looks like the configuration command was inserted somewhere between \usepackage[...]{tex4ht} and \begin{document}, in the root source file. Try inserting it after the \begin{document} or, a much nicer approach, into a separate configuration file.

Foreign content in <TITLE>...</TITLE> elements
Use the \Contribute{TITLE}{...} command to redefine for the these elements the harmful macros that appear in headers of logical units like \title and \chapter. For instance, the definition \Contribute{TITLE}{\def\LaTeX{LaTeX}} for the source \title{with \LaTeX}.

Problems with argument -d... of t4ht
The specified directory must be augmented by a slash character /.

Truncated and empty gifs for Xfig pictures
Some Xfig files are made up of overlapping picture environments, with TeX4ht viewing the components as defining independent figures. The problem can be solved by importing the Xfig files into pictorial environments of TeX4ht.
   \newenvironment{mypic}{\Picture*{}}{\EndPicture} 
   \begin{mypic} \input{xfig-file}   \end{mypic} 

Quality of gifs
The conversion to gif's is controlled by the script
Gdvips -mode ibmvga -D 110 -f %%1 -pp %%2  > tex4ht.ps 
Gconvert -crop 0x0 -density 110x110 -transparency '#FFFFFF' tex4ht.ps %%3 

in tex4ht.env. The quality of the gif's can be improved by replacing `-mode ibmvga -D 110' with another mode having a better resolution. The Metafont file modes.mf, and maybe also a local.mf file, list possible modes (note, however, that your platform might not have all of these modes installed). If you'll just remove the switches `-mode ibmvga -D 110' from the dvips, you'll also likely to get better results due to a higher resolution of the default setting. The dimensions of the gifs can be changed with the parameter `-density 110x110'.