For Modern the HTA study guide is a good source, incredibly indepth for a summary guide.
For Ancient, same deal the HTA study guide is another brilliant source. Ken Webb has also published some topic guides, I know he's done Pompeii and Herculaneum, Minoans and Sparta - not too sure on anything else.
Don't worry too much about having a textbook. Your teachers are bound to give you photocopies equal to that of 5 textbooks. >.> So much paper.