I have a requirement to put data retrieval components in the master page, because I would need this data to appear on each page of the site.
Like Upcoming Events, News Feed, so on. What's the best approach to do it? Should I do custom web part farm solution in VS and put it in the master page? Should I use JavaScript instead? What's the best way to put these components in the master page?
Standard SharePoint web parts on one page I would add the webparts by code using a feature eventreceiver. Create a SharePoint solution in Visual Studio, add a feature and on the "onActivated" event of the feature you add the web parts to the page by code. If needed a user/site admin can still remove the webparts
Standard SharePoint web parts on all pages Create a SharePoint solution with a master page. You can put web parts on your master page by adding the XML configuration xml on the master page. It's a huge topic, google it for some tutorials. (you can also do this by using SharePoint Designer)
Custom functionality on all the pages Create a SharePoint solution in Visual Studio. Create a master page. Create your custom functionality in a user control. Add this usercontrol to the master pages. I would recommend putting the master page and the user controls in the same solution. If the user controls referenced in the master page are not available you get a nasty error. Site admins and users cannot remove user controls from their (master) pages.
I've done this for custom footers and
