Drew Robbins, a former co-worker, has a very nice post about presentations. 

I particularly like two things in the post about how to prepare. First, take someone else's presentation and look at each slide for 10 seconds, and then present on it. If you can present someone else's material with only 10 seconds review, you can present your own content with much less review.

The second part I found interesting was his statement to plan your first five sentences. He says the audience will form their opinion of you in the first five sentences, so plan those out. From there, know the content and speak naturally.