I've noticed that the fonts at this site are different form the font at other S.E sites (which is Arial, I think). So I wanted to know what fonts are used here?
For what it's worth, our almighty ampersand is Baskerville Italic.
Web developers use right-click/Inspect Element on a layout component (such as paragraphs in a question) to see the CSS selectors for the same (or its parent(s)). If you don't see such a menu alternative, there are plug-ins such as Firebug for Firefox that you can install.
Here, using Inspect Element reveals that a paragraph in a question currently uses 100% of 15px = 15px (size in pixels) font size of the primary font Georgia, second choice "Times New Roman", third choice generic Times, fourth choice any serif font. The text color is '#393318' which is hexadecimal notation for a dark gray-yellow color (click the brush color in Photoshop and feed in the number to check). The line-height is 20px, which means 5px line spacing. Between each paragraph there is a bottom margin of 1 em unit, which is a relative unit, currently rendered in browsers as the height of the font of the parent element to the paragraph, in this case, 15px.
To check if your Mac has Georgia, open a text editor and press Command-T.
On a side note, Georgia is the better serif font until we get ClearFace in browsers. I think it's pretty darn good :)