SharePoint 2010 Resources - Ribbon Development
MSDN Documentation
http://msdn.microsoft.com/en-us/library/ee540027.aspx
Blogs/Articles
Customizing the ribbon - Chris O'Brien.
http://www.sharepointnutsandbolts.com/2010/01/customizing-ribbon-part-1-creating-tabs.html
Customizing and Extending the SharePoint 2010 Server Ribbon
http://msdn.microsoft.com/en-us/library/gg552606.aspx - Andrew Connell
Creating a SharePoint 2010 Ribbon extension - part 1 - Wictor Wilén
http://www.wictorwilen.se/Post/Creating-a-SharePoint-2010-Ribbon-extension-part-1.aspx
SharePoint 2010 Ribbon Controls - Part 1 - Summary (multi-part series) - Wictor Wilén
http://www.wictorwilen.se/Post/SharePoint-2010-Ribbon-Controls-Part-1-Summary.aspx
Using RefreshCommandUI with the Server Ribbon (Dallas Tester, Fred Mameri) - SharePoint Developer Team Blog
http://blogs.msdn.com/b/sharepointdev/archive/2011/02/17/using-refreshcommandui-with-the-server-ribbon.aspx
Tokenization in the SharePoint 2010 Server Ribbon (Dallas Tester) - SharePoint Developer Team Blog
http://blogs.msdn.com/b/sharepointdev/archive/2010/12/09/tokenization-in-the-sharepoint-2010-server-ribbon.aspx
Enabling a Button on the Ribbon Based on Selection - Microsoft SharePoint Team Blog
http://sharepoint.microsoft.com/blog/Pages/BlogPost.aspx?PageType=4&ListId={72C1C85B-1D2D-4A4A-90DE-CA74A7808184}&pID=436
Fixed width layouts, the scrollbar and the ribbon in SharePoint 2010. A better way? - web.o
http://www.webpoint0.com/blog/fixed-width-layouts-scrollbar-ribbon-sharepoint-2010/
A Better Enhanced SharePoint 2010 Floating Ribbon - Greg Galipeau
http://www.greggalipeau.com/2011/01/28/a-better-enhanced-sharepoint-2010-floating-ribbon/
Code to Hide the Ribbon and Site Actions Menu for Anonymous Users - Elumenotion
http://www.elumenotion.com/Blog/Lists/Posts/Post.aspx?ID=106
Ribbon customization : Basics - Mano Mangaldas
http://howtosharepoint.blogspot.com/2010/06/ribbon-basics.html
How To Activate SharePoint Ribbon Tab by JavaScript Code - Ingo Karstein
http://ikarstein.wordpress.com/2010/06/15/how-to-activate-sharepoint-ribbon-tab-by-javascript-code/
Sample Visual Studio 2010 project for creating a custom SharePoint 2010 Ribbon tab on runtime (!) - Ingo Karstein
http://ikarstein.wordpress.com/2011/01/14/sample-visual-studio-2010-project-for-creating-a-custom-sharepoint-2010-ribbon-tab-on-runtime/
Additional Ribbon Sample: Custom Ribbon Tab generated by a delegate control that lists all associated list workflows and allow to start a workflow on a selected list item. (Part 3) - Ingo Karstein
http://ikarstein.wordpress.com/2011/03/03/additional-ribbon-sample-custom-ribbon-tab-generated-by-a-delegate-control-that-lists-all-associated-list-workflows-and-allow-to-start-a-workflow-on-a-selected-list-item-part-3/
SharePoint 2010 - Ribbon … becoming a SP2010 developer - Part 3 - Andreas Glasser
http://andreasglaser.net/post/2010/02/21/SharePoint-2010-Ribbon-e280a6-becoming-a-SP2010-developer-Part-3.aspx
Videos
Getting Started SharePoint 2010: Developing Ribbon Controls
http://www.bing.com/videos/watch/video/getting-started-sharepoint-2010-developing-ribbon-controls/10tv8hemv
Introduction to SharePoint 2010 UI Features
http://msdn.microsoft.com/en-us/SP2010DevTrainingCourse_UiEnhancementsIntro
The SharePoint Fluent User Interface
http://msdn.microsoft.com/en-us/SP2010DevTrainingCourse_TheSharePointFluentUserInterface
Module 10: Creating Dialogs and Ribbon Controls for SharePoint 2010
http://msdn.microsoft.com/en-us/sharepoint/ee513157.aspx
Codeplex projects
SharePoint 2010 Fluent Ribbon API
http://spribbon.codeplex.com/
Show or Hide SharePoint 2010 ribbon based on SharePoint Groups
http://spribbonvisibility.codeplex.com/
SharePoint 2010 Print List Ribbon Button
http://spprintlistbutton.codeplex.com/
SharePoint 2010 Custom Ribbon Demo
http://spcustomribbondemo.codeplex.com/
SharePoint 2010 Ribbon Customization with Web Parts for SharePoint
http://www.youtube.com/watch?v=YvAVMF-OBAU
Happy Coding!