I'd apply the same rule, in most cases your font library will fit on a standard dvd if you don't have another drive etc. However I've read that you can also access all fonts if you go to start/run, then type: %windir%\fonts Then you should be given the choice to select them all and paste wherever.
Am I being silly, or does a Mac recognise the majority of pc fonts these days anyway?. In any case, there's a font converter called crossfont (one of many converters), but unfortunately I can't say I've used it, but it might be worth a try, if anything I've read is a good indication. here it is.
Crossfont is the daddy! I can't say I've ever had to use it to create a Mac font as (unless you have something ancient) they recognise truetype and opentype fonts. If you're trying to convert from Mac to PC though it's definitely worth the investment.