Inform yourself about the advantages and discounts the different student-cards offer.

For students

The ISIC card is a card for reductions on travel, museums and major tourist attractions worldwide and is an internationally-recognised student ID card. List of reductions and places to get the card on the website.
http://www.istc.org/sisp/index.htm

For all young people under 26

The Euro<26 youth card opens the door to reductions on cultural activities, shops, transport, eating out and accommodation, and can be used in 34 European countries. Identify those places where you can get the card and the discounts.
http://www.euro26.org