My credo for editing pictures comes straight out of the Hippocratic Oath taken by doctors, First do no harm!  There are several ways to accomplish this, use the camera's built in JPEG as is, Lightroom (or any other similar program),  or  create adjustment layers in Photoshop.  Since I don't feel the need to own or learn Lightroom (my volume of work and the actions and droplets I have created over years of using Photoshop make it unnecessary), I use adjustment layers in Photoshop.

To create an adjustment layer, click your mouse on the half moon symbol at the base of the Layers palette  .                                                 ^

and choose an option from the pull down menu.  When you finish your adjustment it will create a layer that contains that tool just above the background or the last used layer.  You can save the photo as a PSD or TIFF file and keep the layer intact.  The big advantage of saving the PSD file is that you can later go back in and tweak any of the adjustments you made at any time.

On top of the ease of re editing your work, you also can create a layer mask (click on the layer, then click on the object to the left of the half moon that resembles a rectangle with a circle in it. 
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The layer mask is an extremely useful tool in that simply by painting in it using a Black or White Brush you can let the layer beneath the come through unscathed or be completely affected (using different opacities for your brush gives you complete blending control).

Tony Kuyper's website, Good Light Photography  has another method for generating extremely detailed and seemless masks and adjustment layers that produce phenomenal results.  They are extremely versatile and useful.

More on Layers will follow.

Have fun!