If you are interested in developing apps for Office 365, SharePoint 2013 or Office 2013, grab the new Office Developer Tools for Visual Studio 2012 here: http://www.microsoft.com/visualstudio/eng/office-dev-tools-for-visual-studio
Once installed you will find two new project templates in Visual Studio; App for Office 2013 and App for SharePoint 2013. These two templates provide the necessary plumbing to help you get started building new apps quickly.
Building custom solutions using SharePoint 2010 required a local installation of the server software. The new app model for SharePoint 2013 has changed the way developers will build out their environment. Instead of using a local installation of SharePoint 2013, app developers can use a remote SharePoint 2013 server or SharePoint Online tenant. This new capability reduces the complexity of the developer workstation and reduces the amount of memory and software that needs to be installed. MSDN has a great article explaining how to setup a development environment for building apps for SharePoint on Office 365. I would recommend that developers build solutions using the new SharePoint app model instead of the traditional server-side object model based farm or sandboxed solutions.
Server-side object model based farm or sandboxed solutions can still be created if necessary. If you plan to build solutions using the server-side object model then you will still require a local installation of SharePoint 2013. Because of this requirement, the developer workstation will need at least 16GB of RAM; 24GB is recommended. Steps to setup a local instance of SharePoint 2013 for development can be found on MSDN here.
Organizations that are using SharePoint 2013 on-premises can use their SharePoint instance for development. Steps for configuring your development environment and your on-premises SharePoint environment for creating SharePoint apps can be found on MSDN here.
Microsoft has provided very good documentation and samples for developers to learn how to build apps using SharePoint 2013. I would recommend starting with the article titled Build apps for SharePoint. Additional documentation and samples can be found at http://msdn.microsoft.com/sharepoint
Don’t forget that apps you create for SharePoint 2013 can be published to the SharePoint store where you can make money! You can learn more about publishing your apps by reading the MSDN article titled Publish apps for SharePoint.
Leave me a message below or using the Contact Me! link above if you have published a SharePoint app in the store. I am very interested to see what solutions are created.