basically i go for hold. first rule to make profit is buy low sell high. Crypto currency trading needs a lot patience. Buy bitcoin/altcoins when they are low and sell them when they are high. You can use many sites for trading altcoins. like you can buy any altcoin in yobit and check its price on other sites like cryptopia or any other. if the price there is high just transfer then and sell them. remember to calculate the profit along with transfer charge.