The process of cloning organisms might sound complicated but in fact it's not, like I mentioned just now this process is by putting donor adult cell's nucleus in to an empty cell without a nucleus. After this process, the cell will normally start dividing to more cells in the uterus of the surrogate mother and develop until birth.
Animal cloning has also been proved recently that abnormalities are found out from numbers of cloned-animals. The moment when the animal is born might seems normal, but many abnormalities will start to present in later life of the animal. These abnormalities include premature death, liver failure and obesity.
Gray R. & Dobson R. (2009) Extinct ibex is resurrected by cloning, Viewed 18 March 2012: http://www.telegraph.co.uk/science/science-news/4409958/Extinct-ibex-is-resurrected-by-cloning.html
Halim, N. (2002) Extensive new study shows abnormalities in cloned animals. Massachusetts institute of technology. Viewed 18 March 2012: http://web.mit.edu/newsoffice/2002/cloning-0911.html
Hansen M. Ph.D. (2007) FDA says cloned animals are OK to eat. Viewed 18 March 2012: http://www.telegraph.co.uk/science/science-news/4409958/Extinct-ibex-is-resurrected-by-cloning.html
Holloway G. (2002) Cloning to revive extinct species. Viewed 18 March 2012: http://edition.cnn.com/2002/WORLD/asiapcf/auspac/05/28/aust.thylacines
McFarland, Douglas (2000) Preparation of pure cell cultures by cloning. Methods in Cell Science 22(1): 63–66. http://dx.doi.org/10.1023%2FA%3A1009838416621