Firefox Bookmarks

I'm relatively new to the use of Firefox, mainly using the Suites 
(Netscape, Mozilla and now SeaMonkey) but with more and more sites not 
working in SeaMonkey, I find I'm more and more using Firefox.

I like the FF feature where frequently visited sites are shown on the FF 
Homepage (for want of a better/more correct term) .... but I don't want 
it showing EVERY page I visit.

If, for example, I visit www.abc.net.au ... no problem if that appears 
on my Browser 'Desktop' as a sort of bookmark .... but then if I go to 
www.abc.net.au/programs and then www.abc.net.au/programs/thebill .... I 
don't want them appearing on my Browser 'Desktop' as a sort of bookmarks 
.... else my screen might get too cluttered.

How can I stop these additional/subordinate webpages appearing on my FF 
'Homepage'/'Desktop'.

I realise what I'm discussing here is probably NOT real Bookmarks (a 
button for which I see towards the top right corner).... just it seems 
to me it's a reasonable facsimile of Bookmarks so is there a reasonably 
easy way to get FF to do as I desire?

TIA
-- 
Daniel70