laser beam?
 

how do i create a laser beam?
examples : light saber,
i cant figuer it out need help!

You need a material with glow on it. if you're using mental ray you can achieve a better result with incandescence.
Benny

what benny said.

you can change the incandescence colour in the material attributes.
you can add glow using the special effects part of the material attributes.
although, these won't make other things light up.