Select the path and open the Stroke palette and check Dashed Line.
You can enter values for dash length and gap length.
You can click the Round Cap button if you need to make circular dots.
If you need the dashes to have different shapes you would create a new Brush, using the Brushes palette.
With the Appearance palette you can layer additional paths, with it’s own style if necessary.
If you’ll need to use the style multiple times, you can drag the styled object into the Graphic Styles palette, they apply your new custom style to other objects.

911_illustratorpathstyles.zip
Vince
*Please remember to Rate our replies or check Solution if solved. If you get a good idea from the post, consider clicking the Kudos option.