Tom said: "1- the mammoth
What exactly wiped out the mammoth? Several events or one big one? I was reading in a discover magazine that a meteor hit canada with the force of a million nuclear bombs, which wiped out the mammoth, along with other animals of that time. Then why are we finding perfectly preserved mammoths? Because they drowned sometime before the event? Why didnt they know how to swim? Or did the frigid water kill them before they could get out? Also, wouldnt the comet strike have "disfigured" the preserved bodies if the impact was so strong?"

As far as I know, there is no consensus about what killed the mammoth. Mammoths are known to have existed up until around 2500 BC. The leading hypotheses are that they died out due to climatic changes after the end of the Ice Age, overpredation from humans, or a combination of the two. There is also the hypothesis of disease. I haven't heard of a comet that caused a global catastrophe, but even if one did, it wouldn't "disfigure" the corpses outside of the blast area. Cosmic impact catastrophes don't cause mass extinctions due to concussion; they cause mass extinction due to climate change from the dust kicked up during the impact. Unless you think dust disfigures corpses...

"2-Fossilization
Everyone here should know about the preserved tissue that was discovered inside the fossil of a Tyrannosaurus. Scientists also say other fossils from different dinos may be in the same condition. What does this say about fossilization? Doesnt all the meat rot away and the bone get replaced with minerals?"

First of all, there was no "meat". This is a bone. Second, the bone core had been protected from water penetration, which prevented permineralization. However, the tissue was not "preserved". Some microstructures could be seen, but they were not intact cells. The only biologically-based intact material that has been found is heme, which is a small molecule porphyrin-iron complex. While this is exciting, it is not evidence of a young bone. Read the actual articles rather than listening to creationists' *******ization of the results for their own purposes (e.g. http://www.pnas.org/cgi/content/abstract/94/12/6291)

"3-Cloning
Scientists are saying they can now clone the mammoth. How does the process take place? I heard about it briefly, how they plan to put a gamete of a mammoth inside a modern day elephant's egg cell. But doesnt the gamete have to be alive? How do they bring it back to life?"

First of all, I have yet to hear a credible scientist state that they can clone the mammoth. The process of cloning requires an intact cellular nucleus from a somatic (e.g. non-gamete) cell with the DNA intact. If you use a gamete, it's just in-vitro fertilization. The problem is, even in the most well-preserved mammoth remains, the freezing temperatures would have ruptures the cells and sheared the DNA.

"Also, are we now able to clone Tyrannosaurus if we're able to find enough of it's genetic information in the preserved tissue and blood cells that were discovered? Obviously it wouldnt be the same process as with the mammoth. Is there another way to do it? Can we clone other dinosaurs, given there's preserved tissue inside of the fossils? I know we like to keep fossils intact to put them on display in a museum, but making a modern day Jurassic Park would make scientific history."

Right now, there is no Jurassic Park possible, even in the foreseeable future. No fossils with any intact genetic information (much less an entire genome) has been found.

"First of all, I have yet to hear a credible scientist state that they can clone the mammoth."
http://news.nationalgeographic.com/news/2007/06/070625-dna-resurrection_2.html
National Geographic is pretty credible, and this article has both sides of the arguement. Here's the paragraph I love most:
"Five years ago everybody was saying you'd never be able to sequence the genomes of extinct animals ... but here we are. We're not that far away now."
So, will we be able to make a real Jurassic Park in the future?

Re-read the article. The guy did NOT say that we can clone the mammoth. He is SPECULATING that, at some point in the future, our technology will have advanced to the point where we may be able to do so. But we can't now. And, there is a HUGE difference between recovering DNA after tens of thousands of years (mammoth), and recovering it after tens of millions of years (dinosaurs). Never say never, but I seriously doubt Jurassic Park is something to be seriously considering in the foreseeable future.