Swamp Bog is the first map. Right portal leads to the beginning, left portal leads to the far right of Crossroads 1. (The numbers don't show; it's like the haunted house duplicates, they just help you think.)

Crossroads 1 has four portals on ground level, plus several more up above (which can't be reached except by other portals). From left to right, these lead to:
Haunted Hill - Twisted Paths 2 - Twisted Paths 1 - Swamp Bog

Twisted Paths 1 is a flat map with 5 portals in a row, and from left to right these lead to:
unknown - Twisted Paths [?] - Crossroads 1 - Twisted Paths 2 - Phantom Road

Twisted Paths 2 has an identical layouts and the portals lead:
unknown - unknown - Crossroads 1 - Twisted Paths 1 - unknown
This is from what I remember; I didn't actually write it down, so it may be off.

Haunted Hill has 2 portals at ground level, a hidden portal that looks like a signpost, and a third portal at the top of the map. I wasn't able to reach the top portal (you need Teleport) but the signpost leads to Creeping Evil (which is a dead end map with a nice spawn of Leprechauns). The ground portals are:
Bent Tree - Crossroads 1

As for Bent Tree, it has 5 portals (refer to extractions thread). Far right goes to Haunted Hill, far left goes back to the beginning, and upper left goes to Dead Man's Gorge which is the Raven Ninjas' camp. The other two, I dunno.

Bent Tree ->
Dead Man's Gorge->
either Twisted Paths 3 or unknown.

Twisted Paths 3
4 unknown, Forgotten Path.

Forgotten Path
Twisted Paths ?, unknown.

I think the top half of Forgotten Path leads to VoH, but I can't confirm.

Oh BTW, That portal you can only reach via Tele?
Crossroads ?
then the top portals both to Twisted Paths.