Steve Jobs is good at many things, for sure. But as for students of English, he is very, very good at one specific skill: Public Speaking. Jobs has aced all presentations he's ever made. He has just the right intonation, rhythm and makes the best choice of words that make the audience go nuts.If your students don't exactly have Jobs' talent for Public Speaking, making a presentation in English can be a problem, for sure. If you are teaching Business English or preping your pupils for oral exams, there are some websites that provide excellent vocabulary exercises that can help with Public Speaking Skills:
Effective Public Speaking Skills offers free vocabulary lessons that will work magic as homework assignments as it each exercise has a different focus (how to start up, ask for clarifications, etc) and it gives instant feedback. They are all web-based and don't require any kind of subscription.
SlideShare has many ready-to-use powerpoint presentations on how to make presentations, including short ones with hot tips. Those can be quite useful warm-ups or a follow-up for a discussion on the topic.
Finally, on YouTube there are many videos of memorable presentations that can be used in many possible ways for classroom purposes, such as illustrating a topic or as a listening activity. Steve Jobs and Barack Obama always give great and enthusiastic speeches, but there are others who are not as famous as them that are also worth planning a class on.