We all have to give presentations. Some are not as high stakes as others - teaching med students/residents vs. departmental or invited Grand Rounds. Nevertheless, every presentation is an opportunity to improve your skills. There are plenty of materials available on the internet. If you already have favorite articles or videos that work for you, great. If not, here are a few you might want to archive in your collection to refer to when you are about to give a presentation.
If you have an hour to spare, this video by Prof. Patrick Winston (a computer scientist at MIT) is my favorite presentation on giving great presentations.