The fonts are listed in preferred order. One nice thing about listing numerous fonts, is that a character which may not be available in one font will try to be extracted out of the next one listed. The generic font families above are serif, sans-serif and monospace. If your font has more than one word use quotes. Very straight forward, oblique is similar to italic.
Small caps displays the lowercase letters as scaled down uppercase letters.
This property specifies what you want the font to weigh, ex. 50 lbs of pure Courier. Well not exactly, the weight of the font is the boldness, or lightness of the font. There are 5 different ways you can specify the font size. For font-size, ems are equivalent to percentages.