All that depends on how comfortable you are with Photoshop.
What I do:
Open image. Do any color correction. More often than not, its easiest to let Photoshop do it, although sometimes they don't get it right. Thats when you need to go into individual RBG channels (through a curves layer) to get at the meat and potatoes of your image. I would look for tutorials on Color Correction if you are finding Photoshop is mucking things up.
Use Auto Levels. Or if you have the curves layer, you can use the composite RBG to adjust the "brightness" of your photograph. If you are shooting in your cameras RAW format, this is MUCH easier to do BEFORE you get into Photoshop, and should be.
Change your workspace to LAB MODE. From there, apply a "curves" layer. Open it up, and adjust your contrast on the luminosity level - this way it doesn't affect the actual "color values" and lead to all kinds of silly color issues.
If you want to add a bit of vividness to your photos, within the SAME curves layer, choose the A and B level and drag the graph so its input/out is at -100/100 respectively. You'll see the pop in your color.
Then apply your sharepening (while still in LAB MODE) and then convert BACK into RBG, and you are good to go.
Oversimplistic process, but you can use this as a base to do some further research on your own.