If you really want to work wonders with color correction and photoshop, learn how to use lab mode. It's definitely different than RGB, but much more powerful. It's not always the right tool for every job, but it works quite well with flesh tones for people and earthy colors. Here's a GREAT book on the subject:
"Photoshop Color Correction
The Essential Guide for Color Quality for Digital Images"
ISBN 0-321-12401-4
As well as "Photoshop Restoration & Retouching"
ISBN 0-7357-1350-2
And even Older,
"Photoshop Master Class"
ISBN 0-321-13010-3
(worth its weight in gold)
And lastly,
"Digital Retouching and Compositing:
Photographer's Guide"
ISBN 1-932094-19-9
My best advice to you would also look into the use of Hue and Saturation Adjustment Layers, with their respecitve Layer Masks, all set to their color mode "Color", simply paint in what you need in the Layer Masks.
Additive color "theory" hasn't changed that much over the years (or decades depending on how you want to look at it) and understanding that will get you quite a long way. I can pull off things that look perfect by understanding color therory and applying it correctly. It may yield file sizes in excess of .5 gigs, but these days, who's counting?
If I was stuck on an island with one photoshop effect, it would be curves... you can do just about anything with curves, per channel, or to the overall luma.
If you want to play around with other stuff for fun look under Image/Adustments, there you can do photo filters, variations, and other fun things... you can do it all with curves, but this may be more visual for you... especially variations.
Second to Curves its a tie between Hue/Saturation and Levels. Levels, for me, is all about quickly achieving good contrast. Hue Saturation, I mostly use for sepia stuff or to visually run through the gamut of hues a layer can be tinted with.