HTML Styles
The Rich Text Editor (RTE) Format menu allows you to apply styles to your text. You should use Normal for regular body text, and the Heading 2 through Heading 4 styles for your headings.
Here's what a number of common styles look like while working in the RTE:
Image

And here's what that looks like when viewed by the user.
To insert a block of code, e.g. SQL, Java, C++ etc., see the Code Blocks section.