On arrival

When you cross the border into the Schengen area, you will have to present:

your passport with the visa sticker
proof that you have enough money to support yourself during your stay (e.g. cash or a credit card). If you have a guarantee form, you should also bring a copy of this with you.
documentation showing the purpose of your visit, such as an invitation, hotel reservation, etc.
a return or round trip ticket if you are visiting the Schengen area for tourist purposes or private reasons

You may be asked to provide fingerprints by the border control officer, in which case these will be compared with the fingerprints provided when you applied for your visa.
As long as your visa is valid, you can travel around freely in the Schengen area, or in the specific Schengen countries covered by the visa. If you leave the Schengen area, for example to visit the UK or Svalbard, you will need a multiple entry visa.

Be aware that even if you have been granted a visa, the border control officer may refuse you entry into Schengen if you at the time of travelling no longer fulfil the conditions for having a visa, for example having a visa issued by a member state that is not your main destination.

Main destination

As stated above, you should apply for a Schengen visa to the country that is your main destination.

If you are travelling only to Norway, Norway is responsible for your application.

If you are travelling to several Member States, the country that is the main destination either because of the purpose or because of the length is the responsible for your application. Purpose is more important than length.

Business travel and visits to family/friends are more important purposes than a tourist visit, so the Member State where either business or family/friend visit takes place is responsible.

If you are travelling to several Member States for the same purpose, then the length of each visit decides which country is responsible.

If you are travelling for the same purpose and the same number of days in each Member State, the country where you go through passport control to enter Schengen is responsible for the application – and this can be a completely different country that the ones you are visiting, for example if you fly with Lufthansa, you always enter Schengen through Germany etc.

Norway is only responsible for processing visa applications from applicants going mainly to Norway or a country that Norway is representing in the country where you reside.

According to Visa Code article 34 2nd paragraph a visa shall be revoked where it becomes evident that the conditions for issuing it are no longer met.

In addition to creating doubts about the application, wilfully or through gross negligence providing materially false or manifestly misleading information in a case could lead to expulsion from all of Schengen.

Remember to bring with you relevant documents to show at the passport control:

Proof of accommodation
A valid travel medical insurance for your whole stay in Schengen

Your return ticket should be within the period of validity of your visa