Ok,let's use some canon information first,so we can layout a general map:
The kingdoms are actually realms/countries,are located at a very great distance, proving the fact that (as we see in the second book) to travel from kingdom to kingdom, or even just to village, a system of enchanted wells-subways,is needed. In fact, Wonderland exists as a country of its own. The same goes for the Isle of the Lost.
The second detail we always glean from the books is that the Charming siblings' grandparents' palace is specified as "of the east." This, combined with the fact that Raven tells us her parents have separate palaces and subjects, seems to suggest that each kingdom likely has its own hamlets. I mean Snow White and the Evil Queen must share the same realm for plot reasons. So, overall, the geography is likely similar to Game of Thrones,like this:
Now, some personal ideas on the placement of some realms:
> EA's actual realm is in the center and is a neutral zone where everyone goes regardless of their realm. King's Landing likes (keeping with the Got exemple).
> Snow White's kingdom and the Evil Queen's kingdom are a diarchy on the same continent. Lowkey located in the the north, as Snow White is German.
>For the same reason, the two Beauties' kingdoms function the same way, also because the beast in the French version of B&B is a beast for a hundred years, so it makes sense that the two curses align.
>Since they're both Italian fairy tales,Cedar Village is part of Ashlynn's kingdom (the first version of Cinderella, called Cinderella, is Italian, so she's technically Italian). Theirs is a relatively southern kingdom.
>The kingdom of Siegfried of the Ring of the Nibelungs (the canon grandfather of our Charmings) is the largest all and is divided into several fractions,divided among all his descendants. He and his direct heirs hold the eastern fraction, while Daring and his family belong to the southern fraction, coinciding with the White kingdom (hence the Apple×Daring).
> Since Red Hood and Robin Hood are related in this universe, the village of Hoods and the village of the Wolves are both in the Sherwood Forest in the kingdom of Nottingham. Yes, I know Nottingham Is a county, but England doesn't exist here, so Nottingham is directly a kingdom in EAH. Goldilocks' and the Huntsman villages are also located here.
> Wonderland and the Isle of the Lost are archipelagos,they count as independent continents. Same goes for Little Mermaid Kingdom since is under water,and others.
>The Swan Queen's domain is actually a duchy in the north (because: Russia). The true royal families of their kingdom are the Rothbart's and Siegfried's. Since all of Odette's descendants in this universe are theoretically bastard daughters of the prince (for obvious reasons), it makes sense that, as in the Middle Ages, legitimate bastards would have their own duchies+ title of prince/princess.