I would reckoned to read more information about trading on the forum. Here you can find some ways for trading that is checked and bring profit. I don't trade, so I can't advice you any special source.
I don't think that main trading websites lets you to trade with small amount, you should search for one that let's to do that, and then you need to think which currencies you will want to trade and then just wait when price will fall and buy, and sell when price will rise, repeat this and you will get lots of profit...
The problem with a lot of these sites are the deposit and trading fees.
Although it is not much different then large amounts, you need to choose the coin wisely. better to hold many cheap coins, then 1 large/famous coin.