Weißt du wie es Paul geht? - Question structure

Hallo . 

In the question for : Do you know how Paul is , "Weißt du wie es Paul geht?" , why is there a 'es' ? 
Do we not ask - Weißt du wie Paul ist ?

Also , can you please let me know if these sentences are correct : 
Weißt du wie es die Kinder gehen ? For - Do you know how the children are ? 
Sie kennt wo das Buch ist . For - She knows where the book is 
Er kennt das Weg zum Hotel . For - He knows the way to the Hotel
Ich weiße wir  sollen das nicht essen . For - I know we should not eat that. 

Vielen Dank !

Hi Vidya,
I believe that the way it is phrased in German differs from English, in that the literal meaning is "Do you know how it goes with Paul?"  so the es corresponds to it.
It might sound odd to English ears, as it's a bit colloquial. "Paul" in this instance would be in the DATIVE case, which is dealt with more thoroughly later in the course, but it doesn't affect the form of the word. 
Perhaps Julia or Liss can give a more comprehensive answer.

You might have come across "Wie geht es dir?" which is translated freely as "How are you (going)", but literally means "How goes it with you?".  This time you can tell that dir is not in its normal form (du), and it is dative (I think).

For the first sentence you suggest, I believe that would be:
"Weißt du wie es den Kinder geht?" (Not gehen; geht goes with es).
"den Kinder" is dative plural.

The others look correct to me, but I'll see what the experts say! 

Hope this helps!

In addition to Paul's reply I think there are a couple of other things:
Er kennt den Weg zum Hotel . For - He knows the way to the Hotel
Weg is masculine so "den" in the accusative.
Ich weiße wir  sollten das nicht essen . For - I know we should not eat that. 
I think konjunktive II is better here.
Do the tutors agree with our answers?

Hallo Vidya-manuS, Peter--252 und sfpugh,

as Peter--252 points out, "Weißt du wie es Paul geht?" doesn't actually translate literally to "Do you know how Paul is?" Instead, it translates to "Do you know how it goes with Paul?" Because of the meaning "with Paul", Paul  (the object) needs to be in the dative case. (I agree with sfpugh, the konjunktive II sounds better here)

Hope this helps!

Grüße
Julia

Vielen Dank an alle.