Beware of picture fonts and symbol fonts. When someone views your Web page on their computer, they may just see a comma instead of a mailbox if they don’t have the Wingdings font you used to insert cute little symbols. Also, a screen reader will speak the letters you typed, not the Wingdings pictures.
You’ll be pretty safe, though, with common fonts like Arial, Times, Verdana. If someone doesn’t have one of those fonts, the browser will probably substitute something similar.
If you need pictures or non-typographic symbols, use images. See the "Images" section for how to address issues they create. Many typographic symbols, such as >, <, & and £ have special HTML codes that pose no access problems. Unless you hand-code your HTML, whatever software you use to make Web pages will probably automatically create those special character codes for you.