Creating the slides
Put a headline on top of your page (as you see above) because in DiaShow mode, the wiki page title won't be visible (as the whole wiki frame stuff won't be visible, only the page contents).
If you do not want to enumerate your headlines, use #pragma section-numbers off at top of your page.
Don't forget to fill in some valuable content.
For your convenience, there is a SlideTemplate - use it.
Put <<Navigation(slides)>> (upper) or <<Navigation(siblings)>> (lower) at bottom of your page:
|Slideshow ^ |< << Slide 2 of 3 >> >||
|/000 Introduction /100 Creating the slides /900 Last but not least: Running your presentation|