Please ask your questions in the body of the message, not just in the
subject.

You want Custom Animation. Right-click on the edge of the text box and
choose Custom Animation. The rest of what you do depends on the version of
PowerPoint you are using, but it should be pretty obvious with a little bit
of playing.
--David

As well as DM's good advice there's a step by step tutorial here:
http://www.pptalchemy.co.uk/powerpoint_hints_and_tips_tutorials.html#bullets

Regards John