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• German interrogative words are the same with English'.

• Examples.
  • "Wieviel ist diese antike Uhr?" means "How much is this antique clock?".
  • However, "Wieviel?" also fine.
• Vocabularies.
  • "Wann" means "when".
  • "Was" means "what".
  • "Wer" means "who".
  • "Wo" means "where".

• "Wo" is used to asking a location.
• Whereas "wohin" is used to asking where someone is going.
• For examples.
  • "Wo ist das restaurant?" means "Where is the restaurant?".
  • "Wohin geht Herr Benz?" means "Where is Mr. Benz going?".

• Examples.
  • "Gibt es" means "is/are there".
  • "Warum" means "why".
  • "Welcher" means "which".
  • "Wie viel" means "how much".
  • "Wie viele" means "how many".
  • "Wie" means "how".

• Examples.
  • "Hast du geld?" is an informal sentence that means "Do you have money?".
  • "Sprechen Sie gut Deutsch?" is a formal sentence that means "Do you speak German well?".
  • "Wo wohnt Herr Keller?" means " Where does Mr. Keller live?".
  • "Wohin gehen Sie?" is a formal sentence means "Where are you going?".
  • "Wann kommt der nachste Zug?" means "When does the next train arrive?".
  • "Warum muss ich warten?" means "Why I must wait?".
  • "Wann essen wir?" means "When do we eat?".
  • "Wann ist das Treffen?" means "When is the meeting?".
  • "Wie kommt man nach Amsterdam?" means "How do I get to Amsterdam?".

• There is no question that begin with "tun".
• "Tun" means "do/does/did".

• The most pity way is to ask question by changing your tone while speaking. However, this is not a good practice for studying.
• Here is a link to the guide, http://www.dummies.com/languages/german/how-to-ask-questions-in-german/.
• Here is the full screenshot of the guide.