Download and play with the data, have a look at the formulas and understand how they work.
My post below contains the link to an excel spreadsheet which has the calculation for simple moving average for dow jones. Many people asked me for a similar sheet for calculating exponential moving average too. So here it is - the excel sheet with formula to calculate ema for dow jones or for that matter any index or stock.
Its often very confusing as to exactly how we calculate moving average etc. Most sites just say that this is the way, but when it actually comes to doing it, it turns out to be quite confusing, especially the Exponential Moving Average. Simple Moving Average on the other hand is not all that difficult.
To make your life easy I have illustrated how to calculate moving average etc using real data of Dow jones in an excel spreadsheet. Download and see how these are calculated. Pretty simple to understand then.