Guide to learning the fundamentals

Ok,

I need some guidance about learning fundamentals. I know the basic things are GDP, Interest rate differential, etc.

The main pairs I usually look at are

EUR/USD
USD/CHF
USD/JPY
USD/CAD

I want to exactly what kind of fundamentals I need to look at in order to learn more about the pair? How do I measure the impact of each. Any experienced traders, can you please suggest how you started about learning the fundamentals?

Any book, website, guidance.....?