Hmmm, well, let's see. I think first my jaw would just about hit the ground and I'd have to pinch myself to make sure I wasn't dreaming. Then once I'd done that, I would probably race forward with a yell of "Wooohooooo!! Narnia is REEEEEAAAAAL!!!" and dance around in the snow and jump into the nearest snow drift.  (I do love snow, mainly because we don't have it where I grew up.) Then I'd pretty quickly realise — hang on... if this is Narnia and it's winter here, does that mean the White Witch is back as well? And is she still on the lookout for humans?? I'd then quickly retreat into the back of the wardrobe to put on one of the fur coats to keep me warm, for a start. Then I'd want to get really quiet and pray to Aslan to show or tell me why I've been brought to Narnia and what I'm needed for there. Then, well, I'd venture forth into the woods, a bit cautiously, but readying myself to meet the adventure Aslan sends me, hoping I might get to meet Him in person...  

I most likely would wonder if this would all be a dream and pinch myself, then upon seeing all the snow I would be glad there were warm coats to put on. After I put on the coat I would be too curious and amazed to worry about what dangers might be there and run into them! I would be excited to see Aslan and probably engage in a snowball fight with mr and mrs beaver.

Hmmm, well, let's see. I think first my jaw would just about hit the ground and I'd have to pinch myself to make sure I wasn't dreaming. Then once I'd done that, I would probably race forward with a yell of "Wooohooooo!! Narnia is REEEEEAAAAAL!!!" and dance around in the snow and jump into the nearest snow drift. (I do love snow, mainly because we don't have it where I grew up.) Then I'd pretty quickly realise — hang on... if this is Narnia and it's winter here, does that mean the White Witch is back as well? And is she still on the lookout for humans?? I'd then quickly retreat into the back of the wardrobe to put on one of the fur coats to keep me warm, for a start. Then I'd want to get really quiet and pray to Aslan to show or tell me why I've been brought to Narnia and what I'm needed for there. Then, well, I'd venture forth into the woods, a bit cautiously, but readying myself to meet the adventure Aslan sends me, hoping I might get to meet Him in person...

Very similar to my thoughts, lol. I like the snow because I DID have it growing up and don't now, so I'd be in the snow at some point too. I like your second point, about praying; I'd like to think that'd be me too. But I think if I realized I were in Narnia during the Witch's reign, I would be back through that door faster than you could say Christmas.

I don't know if I could face her, not without Aslan around anyway, but I do think eventually, I would have come around. I'm sure I would eventually realize Aslan had a reason for allowing me to go there, and hopefully get back in again. And I mean come on, who wouldn't love their own adventure in Narnia? It would just be too good to turn down! Oh well, I guess fan fiction will have to do for now.

EDIT: I think Courtenay's answer pretty much summed up what most of us are thinking on this subject, so let's spice it up a bit: where in Narnia would you want to go? What would you want to see? Who would you want to meet?

Hmm... if I was truly in Lucy's position, never having known about Narnia, and then I found a snowy world inside a wardrobe... I would definitely still go in. I'm curious. I love to explore, even if it might be a little dangerous.
I think most of us would be confused by the Lamppost in the middle of the woods. But I'm guessing I would stare at it for a few minutes, decide it looked awesome, and then pushed on into the woods.
As to where I'd want to go... I somehow think I'd get along with the dwarfs. Sausage, bacon, apples and sword-forging all have a special appeal.The Shuddering Woods for me!

I think that I would do as Lucy did in terms of taking in the forest and the snow and going for a walk to see what's out there. I'd be different from her, though, in that I'd probably turn back and get something to eat and drink and find my winter clothes before I'd continue on. I've spent enough time backpacking and day hiking that I couldn't see myself just going on indefinitely not knowing what's out there and if there's food and water. Then again, I think it's the enchanting nature of Narnia itself that draws a person in, and if I were to actually encounter the feel of the place that Lucy finds herself in, I might well go on too.

This is a great topic because it helps to explain why Lucy is the one that has to go into the wardrobe first: I couldn't imagine Peter or Susan being as trusting and willing to go to Tumnus' house which sets off the whole chain of events that makes pushing on through Narnia necessary for all four. Edmund may have been tempted by the offer of tea and cake, but it's difficult to picture his early self wanting to spend time with a humble faun and not the queen who gives him exactly what he craves and makes extravagant promises.