Giving a great presentation is both an art and a science. There are many great books out on this subject but the best books in my opinion are by Garr Reynolds (Presentation Zen) and Nancy Duarte (slide:ology), both of whom have new books coming out soon.
One concept I like is The Single Slide Presentation. It is simple, conveys a lot of information, focuses attention on you and your message as the expert, and doesn’t inundate the audience with “death by powerpoint”. For more on The Single Slide method click here and here.