Explain it to me as if I know nothing about Game of Thrones and only have a page from the "A Song of Ice and Fire" wiki in front of me. How would I, after reading the information on that page, figure out that the next clue is the Lannisters? There's not a single word about them there.

The world of "A Song of Ice and Fire"
The Great Houses
of Westeros
Arryns • Baratheons • Greyjoys • Lannisters • Martells • Starks • Tulleys • Targaryens • Tyrells

And yes, Nebo said that the clue doesn't necessarily have to be ENTIRELY from Wikipedia; some things can be figured out associatively on your own. I, for example, don't remember much, but I still figured it out.
By the way, we shouldn't even have the original page in front of us; we only have the Manticore's coat of arms depicted on the shield, and the reverse chain leads quite easily to A Song of Ice and Fire.

And in general, I'm not saying that my solution is 100% CORRECT; it's my job to suggest it