Choose one, and stick with it. Define it by design house, full
name, and (if possible) original source of that font. From then
on, all corporate communications shall use it, and nothing else.
Be precise: 'Times' is not 'Times Roman' is not 'Times New Roman'.
If you need to use typewriters or line printers, choose which
font(s) will be used on each, and do not change it.
Choose a size for body text, a size for headlines, and perhaps
two sizes in between. Maintain these decisions, and your communications
will be more consistent, easier to read, and, believe it or not,
easier to proof-read.
You should determine how the basic paragraph text should look.
Will your paragraphs' first line be indented (if so, by how much)?
How much space should be between lines in a paragraph? How much
space between paragraphs? Be aware that what is appropriate for
a press release might not be appropriate for your year-end investors'
report. Again, it is suggested that you consult with your designer
on this topic.
Corporate
Identity Design 
