Selewe,
One way is to activate the task pane for slide transition, put a timing in
the automatic transition box and hit apply to all.
If you want to build up every slide with a self timed setting, go to slide
sorter view and click on the try-out button, you can easily recognize it as
it has a little clock on it, click the next arrow for every item, say yes
when asked if you want to save the timings.
Now start your presentation and everything should go automatic.
If you want the show to repeat itself automatically go to Slide show -
set-up show and check repeat until escape. Right next to it you can always
choose to revert to progressing the show by hand by hitting the appropriate
radio button.
Luc