Hey man, first of all, good luck!
Be ready to do your pitch with or without graphics, with or without white board,, with or without aids of any kind.
If you were pitching to Steve Jobs, rest assured that after your fourth slide, or 30 seconds of video, he would interrupt to say you're full of shit. Chances are, you won't encounter that kind of abruptness. Just saying, be ready for anything.
Most investors are pragmatists. They will want to know HOW you know that customers will come; they'll want to know what your market research consists of; you'll need to provide some kind of market "proof." Do a mock preso with somebody interrupting all the time to say "That's pie in the sky. Prove to me it's not pie in the sky."
How many customers do you need to make this thing fly? How soon? What's the timmetable? Where will those customers come from? How many will come from each channel? How do you KNOW they'll come? What market testing have YOU done already? Those are the types of questions to expect. (Among others, of course.)
If you don't have those kinds of answers, be ready to tell how you'll get them. What are your income milestones? How can you prove you'll hit them? What happens if you don't? How soon will you be able to prove you're on track? What form does the proof take?
Angels see and hear good ideas all the time. What they want to know is why you're the one to do this and how you know it will work; why this is the right time; why no one else can execute on this; why it will succeed if YOU do it.
Best of luck to you. Hope this helps.