With the advent of computerized typesetting, there has been proliferation in the amount of novelty fonts available to designers. These typefaces often have exaggerated elements that limit their usability as body type for a book or website, but, as impact type, they can have their uses. Find a typeface that matches the theme of your design; if you're designing something for your high school Latin club, use an all-caps typeface with strong serifs to emulate classic Roman script. These kinds of typefaces should be saved for impact and not overused.
Leading is the space between lines of words -- the term comes from the old days of lead-based printing, where slivers of lead would be placed between lines to increase their spacing. For regular copy, leading is traditionally one or two points more than the size of its type, so a paragraph of 10-point type would have leading of 11 or 12 points. Computer design programs can alter leading in a flash, so feel free to experiment with increasing or decreasing it with blocks of display type. Increased leading can let a type design "breathe," whereas decreased leading can create a feeling of stress and discomfort.
Kerning is the space between two individual letters and tracking is the space between the letters of whole words. These elements of a typeface can be altered to either spread out letters or bring them closer to one another. Too much movement in either direction can affect legibility, so use your best judgment when adjusting the tracking and kerning. Like leading, these elements can be changed to give the design more "whitespace," or negative space, and make it easier to view.
Color is a tricky thing with type -- it's very easy to overuse. Generally, any type-centric design should be limited to two colors: black for the design's body type and then an accent color that will draw attention. Color often has a cultural component, so be aware of your audience when using it: while white is traditionally associated with weddings and purity in the United States, it's the color of death in Japan.