How to raise awareness of learning resources through social media?

We are social media interns at the Ben Uri Jewish Museum Art of London and we would like to spread our online learning resource about Holocaust for the Holocaust Memorial Day. We are making an e-blast campaign but we also want to spread it through Twitter. We want to send it to a lot of people who might find it useful but would that look like spam? Do you know any other way of spreading knowledge of a learning resource effectively?