I love Lightroom! It’s easy to learn especially in comparison to Photoshop. Here’s a few tutorials I’ve found helpful. I hope it helps you, too! Enjoy!
Exposure vs. Brightness- http://www.digital-photography-school.com/exposure-vs-brightness-vs-fill-light?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+DigitalPhotographySchool+%28Digital+Photography+School%29
Adjusting Exposure- http://www.iheartfaces.com/2011/04/adjusting-your-exposure-in-lightroom/
10 video tutorials on various topics- http://www.presetsheaven.com/2009/01/08/10-great-video-tutorials-for-lightroom/