Well, you could always read "The Zombie Survival Guide" by Max Brooks. It has plenty of info on zombies, such as:
It is caused by a 100% communicable and 100% fatal virus known as Solanum. The virus replicates in the frontal lobes of the brain, destroying them in the process. The virus mutates the cells of the brain, turning it into a new organ that doesn't need oxygen to survive. It no longer relies on any parts of the body, making it self-sufficent. The virus destroys the brains of animals, or kills them outright. The blood in veins coagulates, as it is no longer pumped through the body. They have no sense of touch, as all nerve cells on the surface have rotted. They can still use theirmuscles, but each time they move them, the get weaker and weaker, as they no longer repair themselves. The virus make sthe flesh toxic to all living things, save a few strains of bacteria that can still stomach it. Most bacteria cannot, increasing the average rotting time of a body from just a few weeks to an average of 5 years. They can survive underwater at any depth, their bodys no longer internally pressurized. They move at an average speed of 1 step per every 1.5 seconds. here is a timeline of the infection:
Hour 1: Pain and discoloration (Brown-Purple) of the infected area.
Hour 5: Fever (99 to 103 degrees Fahrenheit.), chills, slight dementia, vomiting, acute pain in the joints.
Hour 8: Numbing of extremities and infected area, increased fever (103-106 degrees), increased dementia, loss of muscular coordination.
Hour 11: Paralysis in the lower body, overall numbness, slowed heart rate.
Hour 16:Coma.
Hour 20: Heart stoppage. Zero brain activity.
Hour 23: Reanimation.
They no longer relie on organs, so repted shots to the body have no effect. Weapons that relie on a shockwave are no longer effective, as it will not damage any part of the zombie's body unless it is a direct hit or is within the explosion. Dismembered heads will still function, as the zombie will still be able to bite and the brain will not be destroyed. Chainsaws cannot cut through the bone and flesh without getting clogged with it, and lack the ability to cut through the Human skull. Once the gas runs out, they are useless. The noise will attract more zombies. If their lungs still function, they can and will produce a moan upon location of their prey. Unlike us, they relie on all senses equally. We relie on our eyes to hunt. They relie on their eyes, ears, nose, and mouth to hunt. They prefer the taste of Human flesh over animals, and reject any dead body older then 12 to 18 hours. They can use a massive amount of strength repeatedly, as their muscles do not tire as ours do. Thus, they have an all powerful "alpha strike".
Overall, the book takes a very rational approach to zombies, in that they are just genetically modified Humans. They have nearly every sense we have. Their just a modified brain that has no use for the body, an can remain intact while the rest of the body is nearly skeletal. Also, zombies have some kind of sixth sense that allows the ones with absolutely no senses (I.E. The eyes, ears, and nose have rotted away.) to home in on prey. I hope that was informative.