I started out way back when, with Photobase 4.5 (we're talking dinosaur era here), then went with Picassa. Then I outgrew Picassa. I loved its healing/retouch tool (forget what it was called) but eventually hit my limits with what I could do. I did like the "glow" effect one could use to finish a photo in Picassa. I think one of my issues was that the sliders in Picassa were not measure-able; you could use sliders but they did not have any numbers or percents on them; you would just have to "eyeball" the effect. That, and the fact that I never quite understood how Picassa was organizing my photos all over my hard drive made me look for something better.
In time, I got ahold of my first Photoshop Elements, on Ebay. It was about $20.00 for Photoshop Elements 7. It took me about three years to master on my own, but I did find some books on Amazon to help me. Those are always pretty cheap since books about older post-processing programs are yesterday's news.
Photoshop Elements 7 almost killed me; I was on my own, so I began to teach myself the retouching tools, one at a time. I started with the healing tools and learned to use the clone stamp tool as an overall "healing" tool as well. Then I moved on to learning how to use adjustment layers and the blends that go with them.
It did not have "Quick" "Guided" and "Expert" modes like the newer Elements versions; everything was "Expert" mode. Last year, I installed Photoshop Elements 11 which had some advancements over 7 but also some dumbed-down areas. I still use it more than I use LIghtroom 4, which I also bought on EBay last year.
I finally got Scott Kelby's book on Lightroom 4 because THAT is too much to try to teach yourself. Taking my good old time with that. I do put over or under-exposed photos in through Lightroom because Lightroom has more sophisticated tools to deal with those problems. Then I send the corrected photo to Elements to finish it off.
Here are a few places that I found helpful with any version of Elements:
Texas Chicks Blogs and Pics:
Texas Chicks Blogs and Pics ? Making Digital Photography Easy for You! (You do not have to pay for anything, just read through the how-to's, very informative and easy to understand.)
David Peterson's Digital Photo Secrets:
Digital Photo Secrets - Take Amazing Photos with these little known tips and tricks! (You do not have to pay for anything, just read the articles that interest you. I subscribed to the newsletter tips via email. Lots of stuff about how to use Elements, any version.)
As far as Lightroom goes, I do best by following books, but here is the PDF for Lightroom 5:
http://helpx.adobe.com/pdf/lightroom_reference.pdf