I've given a few speeches and briefings. Speak slowly, take breaths, let your pauses be natural silences, don't add in ums, ands, uhs, etc. Have someone you know listen to your speech, let them take a few notes. Remember to vary your voice, nothing's worse than a monotone. Project your voice so everyone can hear you. A good idea is to record yourself in private giving your speech, then you can see/hear if you do anything odd. Or, say your speech in front of a mirror.
A few more things, don't just read from your paper, look at the audience, if you don't want to meet their eyes, then look right above their heads, they'll think you're looking at them.