A prudent person who plans to invest in exchange traded funds (ETFs) has to consider a number of crucial factors. The key items include the measures of performance such as the return on investment and the risk of loss. Another type of concern is the impact of the data set, like the window of evaluation and the sampling period between observations. This primer presents the groundwork for investing in ETFs of any sort in the global marketplace. Moreover, the process is showcased by a suite of top index funds for the emerging markets of Brazil, China, India and Russia.