I agree with the tips hellodepression posted. It's ok if you stutter during the presentation, that's not a big deal, it's if you let it mess with you that it gets you. Easier said then done, but it's a goal to work towards. One trick I like to have is to have some water handy. If I need to take a second and reset, take a drink. If I find myself speaking too quickly, take a drink. It may also help by making your speech mechanism do something else (swallow water) and might relieve some tension. Don't forget to give yourself credit where it's due afterwards. Don't just look at how many times you stuttered, but how many times did you manage a moment of disfluency well? Maybe your fluency wasn't as great as you hoped, but maybe you still got your point across and said what you wanted to say. That can still be a win.