Bible evidence in favour of creationism? I need this sort of information to talk about creationism with an agnostic friend of mine. I know about the passages in Genesis, naturally, but I heard there are some more in the book of Job, somewhere. Also, I believe there are some other passages about creation I certainly haven't heard about.
On Creation
The main text on the subject of creation is the Genesis account. The first few chapters are there to present how God created the world, not to present a twenty-first century scientific thesis. So God provided a simple explanation. A bit like saying that the sun rises instead of talking of the rotation of the earth around the sun.
This being said, this part of the Bible is regarded in many different lights. The first position is the literal position, which says that the heaven and earth were created by God in 6 twenty-four hour periods. This position is held by Answers in Genesis for example.
Another position is that the first few chapters of the Bible are poetry. Then you can believe anything you want on the subject of creation, because the author of Genesis uses poetry as he opens his book.
Then there are positions between the two poles described above:
The rest of the Bible and creation
The six days of creation are quoted elsewhere in the Bible:

Exodus 20:11 (ESV)
For in six days the LORD made heaven and earth, the sea, and all that is in them, and rested on the seventh day. Therefore the LORD blessed the Sabbath day and made it holy.
Exodus 31:17 (ESV)
It is a sign forever between me and the people of Israel that in six days the LORD made heaven and earth, and on the seventh day he rested and was refreshed.

The Bible present Jesus has the author of creation in a few verses. (This make biblical sense because Jesus is the word of God, and in creation the only tool used is the word of God.)

John 1:1-4 (ESV)
In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things were made through him, and without him was not any thing made that was made. In him was life, and the life was the light of men.
Colossians 1:16 (ESV)
For by him all things were created, in heaven and on earth, visible and invisible, whether thrones or dominions or rulers or authorities—all things were created through him and for him.

The passage in Job you mentioned is

Job 40:15-18 (ESV)
“Behold, Behemoth [The ESV study Bible comment on the Behemoth is 'A large animal, exact identity unknown'], which I made as I made you; he eats grass like an ox. Behold, his strength in his loins, and his power in the muscles of his belly. He makes his tail stiff like a cedar; the sinews of his thighs are knit together. His bones are tubes of bronze, his limbs like bars of iron.

Conclusion
From my reading of scripture the Bible supports a literal six-day creation. When did that happen? There are different theories about this as well.
Some argue against a six-day creation, requesting proof. There is no way to prove creationism, but the same is true for evolution. Your position is a question of faith. This being said, it does not mean that you don't ask questions about your position. The starting point of reference in your thinking system, today's science or the Bible, will greatly influence your position.
This might not help you with your discussion with your agnostic friend, but I hope that it helps you in your personal thinking on the subject. Your question is a valid one, but answering it in a few sentences is hard.