Wow, there is a lot of ground to cover!
I'll echo Elie -- one of the great "features" of Lightroom is that it was designed to give an integrated interface to do so much of our "stuff" and so it can be documented quite thoroughly. And it is! For example, there are three accomplished authors who are experts in the software and have each produced great books that can walk you step-by-step through every aspect of the software. I'd suggest getting not just one, but in time each of the offerings by Victoria Bampton (a frequenter of this forum and also a moderater on the Lightroom Users Forum), Scott Kelby and Marting Evening -- Amazon.com will show their books. Working through any on of those books will have you coming out saying "Wow! I know some stuff!" and, when a newbie pops up with a question, you can help provide an answer!
Also, Lightroom Help has been very well put together. I'd suggest not just the "normal" Help tool (it uses online resources) but also downloading the Help .pdf file -- it's actually a bit more "organized" than the online tool, at least it seems that way to me
! Read the Help all the way through, although you may just want to "breeze through" some topics (I've never used the Web page portion, for example).
So, get started -- read up, use the software, and, as has been mentioned, pop up with specific questions! As to specific tips, well, gosh, umm, one early-on thing I did was to develop a metadata preset with contact and copyright info that gets applied as I import. I update it year to year...and, I made sure to set up an Import template for naming photos the way I want so that a few changes for each shoot and I'm ready to go.