Two Part Question about electronics?

Question

1. How can I make a strobe light that can hook up to my stereo?
2. How do I install the strobe light to the stereo?

Answer 1

The lights you describe are also called "Color Organs" and they are available all over in kit form. Check out this page for several types:
http://www.hobbytron.com/ColorOrgans.html

http://www.apogeekits.com/color_organ_light_kit.htm
http://www.apogeekits.com/sound_to_light.htm

Answer 2

I used to have lights hooked to a spare speaker jack on my stereo when I was a teenager. The speaker jacks put output just enough electricity to make the lights work with the music.