I am always reading through the Whitepaper first. Check if the idea is good, if the people behind it are named and can be checked. Transparency is crucial. Also, the actions taken by the community. Support is extremely important for any coin, especially if you are entering some new project and selecting some unknown coin. I have been following an unknown coin for some time now, it is called BTCN. It seems good for now, it reached cmc, has an extremely active community and it is already available in several exchanges. I hope that my gut is not fooling me, but I am predicting some nice profit and good story with this one.