The first step in formulating a search strategy is to take your topic and break it into discrete concepts or keywords. For example, in this tutorial you will be searching for items that discuss power in relation to Shakespeare's play Antony and Cleopatra. The four potential concepts you have in this example are:
Concept 1
Concept 2
Concept 3
Concept 4
Antony
Cleopatra
Shakespeare
Power
The reason Antony and Cleopatra are listed as separate concepts is because you may want to consider them as individual historical figures, as well as characters in the play.