I have been a Lightroom user ever since the very first public beta. I love it. Each power hungry version delivers better conversions and had expanded functionality. It's huge. You can do most things in LR but I would not envisage using it without it's 1st Cousin, Photoshop. For me that's CS5, but Elements 10 has a high percentage of the functionality of the full version. It's no lightweight program.
However, if you're on a Mac, at least do a test drive of Aperture. It's far more straightforward and does very fine conversions and has other useful functions. There are plenty of user guides around online for Aperture.