"thou shalt not kill"
is always my first take. im getting the rest from bible.com, really good site, lemme see what they say, the answers section is good for this-

"Do not be a fool--why die before your time?" (Ecclesiastes 7:17b)

actually , reading the rest , its pretty good, you should just go there.
www.bible.com/answers/asuicide.html

they got a few quotes with fairly decent explanations.
one thing they do point out (accurately) is that the Bible does Not specifically say you will go to hell for it, but other scripts tell us pretty simply yer taking a pretty big hope of being forgiven at the last minute.

-ps hey folks, nice tribe! i am very much into trying to clear things up, and have others help me see things better in terms of the Word.