If you are like me, and you learn better seeing it actually happen versus reading about it on a website or in a book, I can highly recommend
this course. She goes over every module in detail and makes it easy to understand. I loved every second of it.
If you don't mind reading (or neither want to spend the money nor wait for Lesa to offer that course live again) there's a nice set of tuts
here. She's using LR4 instead of 5 but I still learned the basics from that. It's a good start.
I love love love Lightroom, and it can do so much stuff! Good luck.