You could go with Dreamweaver's defaults, i suppose...which allow for a bit more uniformity between platforms:
<font face="Arial, Helvetica, sans-serif">
<font face="Times New Roman, Times, serif">
<font face="Courier New, Courier, mono">
<font face="Georgia, Times New Roman, Times, serif">
<font face="Verdana, Arial, Helvetica, sans-serif">
<font face="Geneva, Arial, Helvetica, san-serif">
_________________________
( o_
/ >) My 84-year-old non-techy mom uses Debian Linux. It ain't that hard.