Q: If I have a wound on one of my extremedies would amputating the limb right after contact prevent me from becoming infected?
A: In short, No. The success rate of this procedure is reported at less than 10% effectiveness, which isn't good odds. Since the alternative isn't any better, that 10% still means there is a chance.

Q: My friend has become infected and is exhibiting symptoms of infection, do I kill him now or wait?
A: The best and surest option is to obviously take him out early so that he does not become a threat, but infected comrades can still serve a purpose. Since they are already infected they make a great and effective way to transport a high volume explosive into the heart of Zombie country (assuming they find this a worth while use of their remaining hours.)

Q: If a Zombie is chasing me, can I escape him by swimming through a body of water?
A: Yes and No. The majority of Zombies are slow, and water will certainly slow their movement further. However, since they are no longer dependant upon oxygen to survive they can indeed cross any body of water they choose to while in persuit of you. Exercise caution.

Q: I saw (insert example here) in a movie or video game about Zombies and it seemed to work great. If I replicated that would it be just as effective?
A: No, what you experienced was faked and in no way possible in the real world. It is too complex and time consuming to construct or execute and you will no doubt be devoured in the process.