I am facing the same question: I'm with IB, and would like to declare taxes correctly. I don't have that many stocks, but given that I did buy gradually (small amounts frequently), and some stocks gave monthly dividends, that would be a loooong list to declare.

The dividends of my (mostly) US stocks were already taxed 15% at source.

How to declare this? Should I list everything?
Can't I somewhere just declare the total value of the stocks I have at 31.12.2014, declare how much dividends I received and how much dividend tax I paid?