study modern code bases of language you want to learn, and look first at their history to see if they are mature, came from a company, academics etc. you shoul

study modern code bases of language you want to learn, and look first at their history to see if they are mature, came from a company, academics etc. you should not only study 'good' code... how will you know what is bad code? study code that does similar things to what u want (client/server/game/ai/datacrunching etc.) and study lot of it..different qualities, ages, and sources