It really just depends on where you want it...
as I don't think there are many 'semantics'
issues w/ css except to compact the code as
much as you can!
Padding works well, as does position:relative;
[which tweaks an element from its orig. posit.
in the flow] but margins are best, as K. stated.
Keep in mind the nagging browser differences
and then lay them out to best suit the project - -
In case anyone didn't know -
top:value; and left:value; wouldn't work w/out a position:relative; or position:absolute; as part of the properties for that element - and units are
needed with the values ;-)