How to have sub-points in a powerpoint presentation

I'm not completely sure because I don't have PowerPoint to test, but if you press enter after the first bullet-point, then press tab, it will do what you want.

Tab only changes the indentation and not the bullet style

Promote bullet = alt + shift + right arrow

Demote bullet = alt + shift + left arrow

If you prefer buttons to keyboard shortcuts, you can also place the cursor in the bullet point that you wish to change the level of, and then click on the "Increase List Level" button.

In PowerPoint 2007, it's on the Home tab, in the Paragraph box, as the fourth item over to the right on the first row. It has an arrow pointing to the right at a set of bars.