You should practice your presentation. You should be presenting your work to the audience, NOT reading from your slides. Be sure you can fit within the allotted time. You've probably heard the old saying "Tell them what you are going to tell them. Then Tell them. Then tell them what you told them." For your presentation in this class, it's more appropriate to say "Lay the ground work. Then explain it. Then summarize the important ideas." Be sure to establish the "big picture" first, before you jump into the details. You may assume an audience of your peers (which means you don't have to define terms and ideas they should already know.) The language you use to describe your project should not be too technical or too "flowery". You will be graded on how smoothly and logically your presentation flows, your organization, and the amount/level of detail you provide. The grading sheet that will be used by your peers and by the instructor will give you more details on how you will be graded.
Overheads should be readable (no less than 18pt font). There should be limited text per slide -- the slide is only to remind you of what you are discussing and to point things out to the audience. A good estimate is 2-3 minutes per slide. Pictures/other visuals should be used (a picture really is worth 1000 words!), and examples should be used when appropriate. Feel free to use the white board in addition to (or in lieu of) slides.
You are to demo your project for the class. Be sure everything you need is set up in advance. You should prepare your demonstration so everything works. Set up time in between presentations will be VERY limited, so you should arrive to class early to get set up if you are presenting the first half. You can set up during break if you are presenting during the second half of class.