Before investing I suggest reading.
Personally my favourites are :
Peter Lynch - One up on wall street
Burton Malkiel - Random walk on wall street
How Buffett Does It: 24 Simple Investing Strategies from the World's Greatest Value Investor

For the life of me I can't finish Intelligent Investor by Benjamin Graham.
Perhaps this is why I suck.
If you like charting (which I firmly believe is useless in long term) then the IBD founder has some books I think.

But if you ask me how much should you invest in US market, my own amount is 90% of my equity holdings, which in turn is around 50% of my liquid nett worth. I have 10% in various mutual funds and PRS type scattered everywhere.

Maybe others can share what good ways to learn about investing (other than paying the fees at the stock exchange).