For BTC, LTC, NMC, NVC, DSH, PPC, ETH, to USD and Interchangeably i strongly recommend www.btc-e.com as it has various ways to deposit and withdraw. Its web-trading should be treated as buying and selling stocks. Further, it also offers https://btc-e.com/profile#meta_trader  which is same as Forex trading, you make money from buying and selling. The good thing is, it allows you to create demo account and let you trade cryptocurrencies pairs in real market without the risk of losing. So if you are a newbie, then go for demo trading for at least 1 - 6 months to understand meta trader different features and have your own workable strategy. Do take educational courses for fundamental and technical analysis learning. Good Luck