You need to have a broad understanding of many different currencies then you have to compare them apples to apples as not all coins are created equal, then you need to decide what direction you think the industry is then you need to figure out potential ROI and invest accordingly. There is no resource to tell you buy this and you'll make this much money, this is all speculation and if anybody tells you they have a sure thing, they are sorely mistaken. Just go with the companies you believe will be widely adopted and don't think its for you because the most value these coins have is in the developing world so you need to think globally.