I need help writing a report on Aeschylus and his plays. I want to get something across about the themes of his plays, which I'm pretty sure is...

Part of the answer depends on whether you are covering all seven of his plays or just the Oresteia. If the latter, you might want to focus more closely on vengeance and justice. As for a theme, all tragedies have some element of human suffering. A play in which no one suffered would not be a tragedy. Thus you might want to narrow your focus to emphasize that Aeschylus, more than the other Greek...

Part of the answer depends on whether you are covering all seven of his plays or just the Oresteia. If the latter, you might want to focus more closely on vengeance and justice. As for a theme, all tragedies have some element of human suffering. A play in which no one suffered would not be a tragedy. Thus you might want to narrow your focus to emphasize that Aeschylus, more than the other Greek playwrights, seems concerned with the relationship between divine justice and human suffering. 

For your report, you might begin with what little is known about Aeschylus' biography, including his dates, the number of plays he is known to have written, and a list of the seven plays of his that have been preserved with brief summaries of all seven.

Next, you might want to place him in context by describing the state of Greek drama immediately before he began writing and then discuss his innovations. Some of the most crucial were introducing a second actor and adopting the third actor introduced by Sophocles. You should also cover his distinctive features, including the stately, ornate use of language and invention of many compound words, the habit of writing connected trilogies, and the radical innovation of his Persians, which is our only extant Greek tragedy set in a contemporary rather than legendary period. 

You should conclude with the thematic discussion of his plays.