Don't always look for shortcuts the results are rarely as good
if you can manage this it will save a lot of grief in the long run.
Phil & Craig are right, photoshop is too big to sit down and learn - and it's too easy to ruin your pictures with it.
I'll go further and say it's more helpful to develop the skills to work out what you want to do to your photos and why rather than working on a set of photoshop techniques 'cos Phlearn says they're possible. To that end get lots of feedback & critique on your own work, and watch as many online critique videos as you can find. But approach the videos with a critical eye - don't believe everything you watch!
Just 'cos you can remove blemishes, soften skin, sharpen and brighten eyes, reshape eyebrows, tidy up hair, add some fake flare, fiddle with the local contrast and add some film-effect toning it doesn't mean you should. Much better to be able to look at an image and work out what changes you want to make and why - and then go and look for a tutorial to achieve it.
For instance, if I were to look at an image and decide it needs skin redness improving, a bit more contrast and 3 dimensionality to the face and perhaps a bit of work to bring the colours together then I could set about looking for specific tutorials to those ends.
In fact.. do as I say, not as I did