To mix together clips, you can use youtube video editor http://www.youtube.com/editor or local software like http://www.videolan.org/vlmc/ or http://www.lwks.com/
The key thing here is that your source material demonstrates to the judges that some of the end result was your own work and that it is possible for another person to replicate that work.
The best high level reference is the 'Understanding Data' and 'Delivering Data' chapters of the Data Journalism Handbook which is available online for free at
You can learn the technical skills from scratch in Visualize This: The FlowingData Guide to Design, Visualization, and Statistics by Nathan Yau or for more advanced
interactively with websites like [http://www.codecademy.com/](http://www.codecademy.com/#!/exercises/0). for JavaScript or [http://www.learnpython.org/ ](http://www.learnpython.org/)or [http://tryruby.org](http://tryruby.org/)
[https://developer.mozilla.org/en/JavaScript](https://developer.mozilla.org/en/JavaScript) - especially for web applications and visualisations, you'll need a basic understanding of JS. Common libraries like prototype or jQuery can help
WCAG guidelines not only make a web app accessible but make it a better experience for all users! Even if not making an app, good to consider these things to do and not do: [http://www.w3.org/TR/WCAG/](http://www.w3.org/TR/WCAG/)
Some people like sensis [http://](http://developers.sensis.com.au/)[developers.sensis.com.<wbr>au</wbr>](http://developers.sensis.com.au/)[/](http://developers.sensis.com.au/) use a provider like[http://](http://mashery.com/)[mashery.com](http://mashery.com/)[/](http://mashery.com/) or [https](https://apigee.com/)[://](https://apigee.com/)[apigee.com](https://apigee.com/) or [http://](http://apiaxle.com/)[apiaxle.com](http://apiaxle.com/)[/](http://apiaxle.com/) or [http://www.3scale.net/](http://www.3scale.net/) which handles making a good API for them.
- Many web app frameworks can generate the documentation for you. For example Symfony for PHPhttp://symfony.com/ https://github.com/FriendsOfSymfony/FOSRestBundle http://williamdurand.fr/2012/08/02/rest-apis-with-symfony2-the-right-way/ https://github.com/nelmio/NelmioApiDocBundle better apis https://github.com/liip/LiipHelloBundle
Also check out [http://thejit.org](http://thejit.org/) & [http://www.senchalabs.org/<wbr>philogl/</wbr>](http://www.senchalabs.org/philogl/) (contributed by Matt Adcock)
[![Planning Alerts Screenshot](img/How-to-participate-in-GovHack_html_2f0199ff1-300x221.png "Planning Alerts Screenshot")](img/How-to-participate-in-GovHack_html_2f0199ff1.png)Description: Planning Alerts takes data from local government development applications and sends alerts to users based on what applications are lodged in their area.
Description: Displays connections between government contracts, business details, politician responsibilities, lobbyists, clients of lobbyists, political donors and the location of these entities.