Text - Fonts - TypeFaces
What fonts are considered 'Web-safe' and which code conventions conform to Web standards and accessibility guidelines?
You could always rasterize your text and stick it in your web-pages in graphic files, but there are some pretty drastic consequences of doing that. The main one being that crawler-based search engines, like Google, MSN, etc, don't read text in images. Therefore, if getting referrals from search engines is at all important to you the first potentially major compromise you'll have to make is the selection a typeface or two from the rather limited set that are generally regarded as universal or 'Web-safe'.
Default fonts
By default most browsers will use Times.
The simplest styles that can be applied are serif, (Times is usually the default serif font so you should see no difference from the default style), sans-serif, (often Arial by default), and mono, (which doesn't seem to do manything useful on its own).
Apart from Times and Arial other defaults can be invoked by using the <code> and <pre> tags. In these cases you are likely to see the monotype or 'fixed-width' font Courier.
Alternative fonts - sans-serif
Verdana - similar to, but slightly rounder and more spaced out than Arial, Verdana is probably the most commonly used font on the Internet. I used Verdana as my by default as it works extremely well on screen at a range of sizes.
Geneva - can look like a cross between Courier and Verdana.
Lucida Grande - distinctly different from Arial, Verdana and Geneva, but not to everyone's taste of course - but then what is?
Helvetica - this classic typeface can look a bit cramped on screen with some browsers stuggling with the letter-spacing. Helvetica is often listed in style rules as a secondary, fall-back font for systems that have Helvetica but not Arial.
Alternative fonts - serif
Times New Roman - not much of an alternative to Times
Georgia - fatter and rounder than Times, a bit cheekier and less formal.
The lack of alternatives to Times is possibly due to readibility issues with serif fonts. It's also worth remembering that lots of devices just don't do serifs, e.g Palm handhelds.
Is that it?
Sort of. There's nothing to stop you specifying any font you like. However, if you're as cautious as most people seem to be you have to play with line-height values, padding, spacing, colour and the use of italics to achive the best look you can.