I hate it when I get a cold!  As soon as I get the sniffles I take Vitamin C to fight it.
That's a good idea. There is some evidence that regular use may shorten how long a cold lasts.
I just take whatever amount is in a vitamin.  How much should you take?
You might want to read that bottle. I'm not exactly sure of the correct dosage, but too much may cause stomach discomfort, headaches, trouble sleeping and skin flushing.
What else can I take to prevent the common cold?
Best evidence currently out there shows the best prevention to be handwashing.
How frequently should I wash my hands?
Hand washing
Hand washing (or handwashing), also known as hand hygiene, is the act of cleaning hands for the purpose of removing soil, dirt, and microorganisms. If water and soap is not available, hands can be cleaned with ash instead. 
Medical hand hygiene refers to hygiene practices related to medical procedures. Hand washing before administering medicine or medical care can prevent or minimize the spread of disease. The main medical purpose of washing hands is to cleanse the hands of pathogens (like bacteria or viruses)
to try it by his friend John Frankenheimer. "He said I should do some TV, that it could be fun as long as you take the same care as you do with feature films--get good actors, do something that's going to be special. It was good advice."
He discovered a friend of his, John Mortimer, had just written a script of "Don Quixote" and offered it to Yates to read. "I did, and I really liked it," said Yates.