Some font families include fonts that consist of just ligatures, example below
http://farm6.staticflickr.com/5312/7440981382_48c2b497ce_z.jpg

What's the right way to use them?

hi !
have a look here : http://en.wikipedia.org/wiki/Typographic_ligature

no you misunderstood, I know how to use ligatures but how do I use these fonts where the entire font is just ligatures. Several families have that, like this http://www.typography.com/fonts/font_styles.php?productLineID=100020

Well, as far as I'm concerned, if you take a look at Requiem, the "Requiem Italic Ligatures" should be used with "Requiem Italic", at least that's how I see it But then, you can use them the way you want, there are no rules. Well, yes, there are "rules" but you can break them too

Ahhh why can't I clearly express my thoughts today
I meant the workflow... let's say I'm setting a header in requiem and I want to see all available ligatures for the combinations of letters in my copy. What do I do? Typing with the 'ligature' font produces random ligatures....

depends on the software you are using. Illustrator and Indesign have a "Glyph" panel.

Back to Lisboa, as far as I can remember that one started as a postscript family and the later OTF versions followed the postscript fonts. Ergo, I think there was never a real OTF version with the ligatures included in one and the same font file. The ligatures font file only has the standard lowercase of the Lisboa and a series of f-ligatures in the capitals so the only way you can use the f-ligatures is using these corresponding capitals.