The REAL history of currency is as old as mankind. It's impossible to know it all.
Even though it's a shameless plug, check out my economics hubs - they will answer a LOT of your questions about money.
Another resource to check out is mises.org. There are months, if not years of media to ingest related to money.
To understand how money today became money, you need an understanding of Ludwig Von Mises' Regression Theorum (I wrote an article about this recently). Basically is simply asks the question "how much will something cost tomorrow?". The answer is "pretty much what it cost yesterday".
If you keep applying the answer to the answer, money is worth what it was worth a long long time ago; and we discover that money's original value stems from when the money was a commodity just like anything else.
Gold used to just be a pretty metal that people used as jewelry, and this is where it's value stems from. It was so popular that people began to use it as a Medium Of Exchange (that is, they would trade for gold even if they didn't want gold itself. ... check out my articles).
The first PAPER currency in the WESTERN world that we know about dates to the colony of Massachusetts. I'm not kidding when I say this: the colony literally would send raiders up to Quebec to attack and steal from French fishers on a yearly basis. They would then divvy up the loot to the raiders to pay them.
... until one year the raiders failed to overtake the French. This caused a great stir! As Murray Rothbard (an Austrian Economist) puts it "one thing that history has taught is that having a bunch of armed soldiers who aren't being paid is a recipe for disaster".
Massachusetts didn't have the hard currency to pay them (gold was money), so they printed up sheets of paper saying "we promise to pay you gold as soon as we get it!"
... of course they failed to live up to the promise, and an inflationary boom and bust hit the colony a decade or so later.
-- ANYWAY, check out my hubs. If you're interested in money, you'll probably learn something from them.