I've recently learned to write my own WebControls, but I'm still hazy on the difference between Render and RenderControl. I started out using Render, but at some point I started using RenderControl, which I now use exclusively. If I'm forming a bad habit I'd like to nip it in the bud now before I get set in my ways.
Here's a good read: Render vs RenderControl
Excerpt from links:
The Render method enables the controller to render itself by writing HTML output to the response stream. This passes a reference to the HTMLTextWriter object, which can write directly to the response stream. This method should be used when you derive directly from control.
The RenderControl method is used by the page to render each individual control. It allows the consumer of your class to render it, and you can use it to render the child controls if you're using a composite control. Also, one thing to note is that this will not be invoked if the visibility property on the control is set to false.