Yup--you can put a line in your style sheet that defines the tag <p> as "Verdana, 10 pt, bold, 1.5 line spacing" or something like that. Then just embed the sheet in your page and everything within a <p> tag will appear in the preset style, unless you override it some other way. You can also define a series of fonts, so if a user's system doesn't have a specific one (like Chiller or Lumos) the text will display as an acceptable alternate.

My ficpage and the sadly DOA Huffleclaw FQF use CSS, tho' I haven't done anything really complicated with it so far. I find it nice for doing font colors, so I don't have to keep retyping the hex code, and also for defining <em> and <strong> tags so they're actually, you know, useful.