This may seem kind of stupid, but I can't seem to find a way to enter the Venomous Vines area on the map screen. I can't use the hand icon, and have walked all around the area trying to find the entrance. Any help would be appreciated.

If you don't know what I am talking about, a map of the game is located here:
http://www.sierrahelp.com/Documents/Maps/QuestForGlory/QfG3Map.html

Try walking to either V or N from the link you provided, you should arrive there. If that fails, move to the south of the rocks, then travel to a point north of it. You'd either stop as you encounter it, or if you move to avoid it, you know which point is considered the venomous vines.
Can't really recall having that problem, though I recall entering areas I didn't want to. Hope you manage to get there soon.

I never tried walking around the area of the rocks, I simply would click the walk icon on the rocks itself and my hero would arrive there automatically.

What cnquist said. That map is incorrect. The venomous vines are located in the smaller rock formation to the south.

That's correct. It should take one whole game day to travel back and forth. So if you leave in the morning you shoud arrive back at Tarna when it's night time, IIRC.

Thank you so much!