PDF graphic nightmare

[Tom Herme <therme -at- NVBELL -dot- NET>]

Fellow Techwhirlers:

My questions are lower in this post, first here's the situation.

I have many bitmapped screen captures in my software manual developed
using Word 8 (Word 97) that appear just fine on screen and when printed.
However they appear degraded (both on screen and when printed) after I
write to Acrobat PDF. By the way, the PDF'd text is acceptable but could
be better. I attempted to use Distiller but receive the same results
even when I fiddle with all the settings for resolution, compression,
etc.

The bulk of the screen captures were developed using these tools and
this process:
My display settings are 800 X 600, 256 color. I do a Alt + Print Scrn
into RoboHELP 4.0's screen capture tool where I clip the image I want to
use. I then copy/paste into Word 8 (Word 97) and scale as necessary.
Occasionally I paste the image into Visio 4.0 where I will attach
callouts prior to pasting into Word and scaling. The callouts appear
very crisp and sharp, something for which I have no explanation, unless
the callouts are actually another graphic format.

My questions are these:

(1.)  Has anyone succeeded in making such images as I describe above
appear clearly in a PDF file, using either PDF Writer or Distiller? If
so, how did you do it?

(2.) Do I need to redo all screen captures in 600 X 480 at 16 color?
Would the resulting images in PDF files appear clearer?

(3.) Is there a PDF FAQ somewhere that provides definitive directions
for working with these graphics?

In searching for solutions to this problem, I find that I'm not alone.
Many others have these problems. If this is a problem with Adobe, I'd
like to know. Otherwise if any of you have a usable process, I'd
appreciate knowing what that is.

Please respond on list and not to me personally. I'm sure there are
others who would like to see responses.

Thanks for your help.

Tom Herme