Here is a list of resources on how to prepare to give a talk.

• Kristen Grauman – Tips for Preparing a Clear Talk ◇ slides · video
• Patrick Winston – How to Speak ◇ videos · see, especially, his big four heuristics.
• Ranjit Jhala – (An Opinionated Talk) On Preparing Good Talks ◇ slides · video
• Gary Bernhardt – How to Prepare a Talk ◇ article
• Iain Murray – Speaking Resources ◇ notes

The following references are listed also in Iain's post, but I'll mention them for completeness:

• Matt Might – Ten tips for academic talks ◇ article
• Jonathan Shewchuk – Giving an academic talk ◇ article
• Sharon Goldwater – Advice on designing and giving presentations ◇ article