if you use slides i suggest reading cliff atkinson's blog "beyond powerpoint bullets". in it he lays out ideas, principles and templates for PPTs (and any other preso tools) that tell stories. these are based on cognitive studies, like the number of bullet points you should use based on how much your audience can hold and remember.
secondly, advice from one of my ph.d. advisors: "tell 'em what you're going to be telling them, tell them, and then tell 'em what you told 'em". the take home message is not a punchline, so don't be afraid to "spoil" it up front and repeat it.
don't read your slides, use images (see the first paragraph) and tell a story. talk with passion, enthusiasm, and joy. RAVE: rate, articulation, volume, emotion (from mrs hedaman, my old theater teacher back in high school), remember that.
love what you do, and share that joy with your audience. that's the goal.