Dot Net Nuke has a bunch of built in Controls that you can use in your custom modules during development. A little birdie told me that they are really just Telrik controls wrapped with dnn stuff. Not sure if that is true or not, but either way here is how to add them to your project.
Step 1) Create a new module project or open an existing one.
Step 2) Open the designer view of any of your pages.
Step 3) Ensure that your toolbox is open and then right click>Add Tab and name it as you please. This tab will house all of the controls that are built in from DNN.
Step 4) Right click again within the toolbox and select the “Choose Toolbox Items” option. A dialog box should pop up.
Step 5) Locate the Browse button and locate your DotNetNuke.Web.dll and DotNetNuke.Web.WebControls.dll in the bin folder of your site. Once selected press open and then “OK”.
Ta-da, now you have all of the built in DNN Controls right there to your left or right. Enjoy!