Hi jitasb
Glad you like it so far.
The Strategy is relevant to the cash chart and is charted daily by Chartman, this is just a summary of the daily review.
You are correct that you should chart the relevant market to the trading instrument. With that in mind most folks have been SB'ing the dow. Alternatively you can chart the dow and trade the futures, dow or ES, as the SB price is taken from this anyway. (loosely speaking lol)
It is a good place to start and get used to charting and its idiosyncrasies
HTH
NB