my roommate has a juniper bonsai tree and it is turning brown.

Sorry, it is probably dead.

i know that it should not be in direct sunlight. but i dont know exactly how
much water he should give it daily. also i am thinking about getting a
fluorescent light for it but i would like to know the correct wavelengths for
the tree or which bulb would be best. its not a very big one, but should it be
clipped regularly?

Encourage your roommate to try again. However, do not try to keep a juniper
indoors. If you want to grow a juniper bonsai, it needs to be outdoors for the
summer and dormant in the winter. If you want to grow an indoor bonsai, get a
Ficus, but it will still do better if you keep it outdoors for the summer and
under fluorescent lights for the winter. Come back next fall & we will tell you
more.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)