Step 1

Camera-raw was designed to work with .RAW extensions but we can use for work with .jpg ant .tiff. To open your jpg file in camera-raw on windows, go to "File/Open As"" and choose "Camera Raw" in "Open As" text input and choose your jpg image. In MAC go to "File/Open" and choose "Camera Raw" in "Format:" drop down. For this tutorial we will use this image http://www.sxc.hu/photo/971726 from sxc.hu

Step 2

All adjustments should be based on the point of view of each designer, and I will make changes to get interesting result for my taste. Our image have a strange green and blue aspect and we need to fix this. First step is get the correct white balance.
We have two ways to do this, one is using "White Balance Tool" and click in some light-gray color in image. Other is using predefined balances defined in "White Balance" drop down. I choose "auto" in "White Balance" drop down(when use .RAW image instead .JPG you have many other predefined balances).

Step 3

Now we need to adjust the exposure, to do this we use "Exposure" control. I change the exposure value to 1.30, but when i do this the image lost many details. To fix this problem use the "Recovery" control. Camera-raw has cut-alert when you starting lost details, move Recovery control to the alert disappear(for me 43).

Step 4

I think the most important steps are 1-White Balance, 2-Exposure Control, 3-Recovery and 4-Blacks. For me this picture have good black's now and i don't need made changes. But i think we need more vibrance, fill light and constrast. Slide "Fill Light" to 21, "Contrast" to +8, "Vibrance" to +7 and "Saturation" to -13

Step 5

Now i think the result is good but we can reach more details. Go to "Details" tab. When you use .RAW files you have more controls in this tab, for this picture in JPG we olny change the "Amount" to 40

Step 6

For me, now everything is good in that image. To finalize you can save your new picture using "Save Image" button, in that window you can select the extension and the name for images when you work with more than one image. "Open Image" to open the new image in Photoshop document and "Done" button to continue editing this image in Camera Raw later.

Finishing

Camera-raw is really powerfull tool and is too big to talk everything in one tutorial, you can do many other things and cool adjusments with this tool. For us this adjustments are good but to get more informations about camera-raw, i recomend read second chapter in "Adobe Photoshop CS3 Book for Digital Photographers" by Scott Kelby