When to use custom nodes? How to display custom fields?
Best suggestion, don't start doing custom template overrides. With site building tools like Display Suite, you no longer have to continue writing custom node templates. By using Display Suite, you can set a view mode you defined to a two-column template, and then set the fields you'd like into each region.

You can see in the example below how easy it is to achieve something like this without having to build custom templates. Of course if you need to do anything extra, you can always customize on top of that.