I can recommend wholeheartedly The Presentation Secrets Of Steve Jobs.
This book pretty much sums up the current cutting edge approach to presentations - honesty, passion and preparation. External appearance doesn't matter so much as authenticity.
There are also tips on how to organize a presentation. For example, define an enemy or problem and
show the audience how your idea overcomes the problem. Also create an a-ha moment that the audience can take home with them mentally.
Along the way, the book also discusses the correct use of slide images and text behind you and the correct use of props. Lots more in this one - check it out.