From the Adobe Photoshop Lightroom YouTube Channel:
Lightroom tips and tricks in 60 seconds or less from longtime Lightroom team member Benjamin Warde.
Note: The sound is extremely low on this video, so low that it may be hard to hear for some.
With that in mind, here's the tip – you can use the CAPS LOCK key to cause Lightroom to auto advance to the next image after rating. [Sean]
The Creative Cloud Photography Plan (Photoshop CC & Lightroom CC) is an excellent value at only $9.99/month.