Handling questions
If you follow my advice in the "Keeping your audience's attention" section, you're likely to get questions during your talk.
Some speakers fear questions. They worry they'll disrupt their rehearsed routine. The solution to this is the same thing that fixes most speaker concerns: practice more.
When you get questions, it's important to do two things:
Repeat the question. Unless the venue is tiny or the asker is amplified, repeat the question so you're sure the audience knows what you're answering. Lots of speakers forget this! Remembering will make you seem like a pro.
Respond graciously. Keep in mind that other people with questions are watching to see how you treat the asker. I try to respond in the friendliest way possible, even to challenging or somewhat antagonistic questions. I'll often compliment the person with "great question!", or thank them for asking it.
One other trick I've used to encourage questions is outright bribing. I'll bring couple cool t-shirts and explain that I'll distribute them for great questions. This usually works extremely well.
One final note: if you're in the middle of an important point you want to make, don't be afraid to acknowledge someone with their hand up by saying "Just one sec on the question." You can also acknowledge them non-verbally with nodding eye contact and a raised finger (not that one). Don't let questions interrupt an important or dramatic moment in your talk. When you're on-stage, you're the boss!