I've captured footage but every time I drag and drop the clips into the timeline it comes up with the red bar at the top and I need to render all the clips. This will take hours as there are many many clips. Any advice on what I may be doing wrong or a setting that I need to turn off/on?

The most likely is that your source material doesn't match the settings on your timeline. Look closely at the red render bar/s. The upper is video, the lower is audio. It may be one or both that needs to be rendered.

Just double check your sequence settings and make sure they match your source material format.

-gb-

Thanks Greg. You are exactly right. My timeline settings were at 23f while my capture rate was 29 frames. Much appreciated.