Reddit reviews Vision & Voice: Refining Your Vision in Adobe Photoshop Lightroom (Voices That Matter)

If you're a lightroom guy, master the general panel in the develop module. The basics of color balance, contrast, highlights, black point, fill light and the differences between exposure and brightness for example, will put you ahead of a large chunk of the other folks out there.

Don't worry about technique as much as making the image match your vision, a great book on this is Vision & Voice by David Duchemin (fellow Vancouverite). The book goes into how it's ok to change an image from blue to brown for example if that matches your vision of what you were trying to create.

Pardon that diversion :) Hope the above helps.

The most important ones though are in the general panel, bringing in image to life from the "blah" that it tends to come out of the camera with. As jnphoto mentioned, shooting in raw is pretty important if you're learning PP, gives you the most image data to deal with.

HTH, HAND

Here are the only two I have read specifically for lightroom, I highly recommend both:

for workflow and basic functionality (workflow isn't as sexy as editing, but if you get a good system down, it will essentially become second nature and allow you more time for editing):

Lightroom 2: Streamlining your Digital Photography Process

For the creative process: (arcterex already mentioned this one.)
Vision & Voice: Refining Your Vision in Adobe Photoshop Lightroom (Voices That Matter)

Anything by David Duchemin is great, he also has a blog and some great ebooks

This is a good blog also:
http://lightroomkillertips.com/