Following last week's online photo processing workshop, I sent out this list of tips and some info about the tools I use on nearly every photo I plan to use. Every day I use some version of Photoshop or Photoshop Elements. The items below are in all of them except for any Photoshop prior to CS (v.8).

Exposure:
It is always better to underexpose in the camera than overexpose. Turn on the histogram in your camera's display if your model has one (check the manual). In Photoshop/Elements use Cntrl-L for levels to see the histogram. Slide the white/black pointers to the nearest pixels--go beyond a little bit if it looks OK. Slide the gray pointer for mid-tone adjustments. Use the Preview check box to see before and after your fiddling with it.

Use Shadows/Highlights adjustment:
Unlike Brightness and Contrast which affect the whole image, Shadows/Highlights adjust only their respective areas.

Dodge and Burn:
Use these tools to make spot lighting adjustments. Dodge (looks like black lollipop) lightens and the hand making a hole Burns.

Brush Sizing:
Use the [ and ] brackets on your keyboard to enlarge or shrink your tool brushes. If you want to have fuzzy edges and blend what your brush is doing, use the hardness slider toward 0 for less hard edge or to 100 for more hard edge. Remember, once you select the tool, settings you can adjust will appear just above the image window.

Zooming in and out:
To quickly adjust your view of the image you are working on, use Cntrl+ and Cntrl- (control-plus, control-minus) to zoom in and out. Look at the top of the image window and remember to check your image at 100% sometime before you finish working with it. If you see blocks of pixels you pixels are too big, you have too few pixels and you severely degraded your image. It will look that bad when used/printed.

Image Size:
Crop and resize at once with the Crop tool. Once you select the tool, put the size you want in the settings above the image. 400 px Width and 300 px Height would half-fill a web page. 1024 x 768 is a full PPT slide. For print, use inches and 150 ppi for poster printers, 300 ppi for professional printers. On some personal printers, 200 ppi will be fine. Keep in mind, professionals and the media will want 300ppi.

Compression:
For a terrific compression utility, use Save For Web. There you get side by side comparison of original and compressed. Only do this for on-screen images, not print.  Compression is lossy---data is thrown away and not fully recovered.

File Types:
RAW--used by professionals most concerned about quality and flexible use of the files. The files are very large and the data collected is not compressed. Cameras that fit in a shirt pocket do not usually have it as file format choice, but some do.  RAW is not an option if you operate your camera in Automatic. Manual is also preferred by professionals.

TIFF--not as commonly found as an option in cameras as it once was. However, this is the format most commonly used for professional quality printing since it is not compressed.

JPEG--common to small cameras. If you have this lossy compressed file format as your camera's only choice, it is best to shoot in the highest qualtiy settings. That means shot the highest dimensions your camera will allow, using all the camera's megapixels on the sensor (you paid for them!) and set the "quality" to superfine or smooth, or whatever is the farthest away from basic or normal. 

If you start with a JPEG, after you've made adjustments in Photoshop (or whatever) save the image as a PSD or TIFF to preserve the quality. Saving a JPEG as a JPEG with compress a compressed file and the quality will degrade as you repeat that process.  Use PSD or TIFF as an interim format until you are done make adjustments (today, tomorrow and beyond) then output for final use--TIFF for print, JPEG for PPT or the web.  I will typically have the original file saved untouched, and a PSD version if I want to preserve layers, and a TIFF for print, and a JPEG for electronic use.  Yes, 4 versions for important images. I usually leave the filename the same for all of them with only the filetype extension different.

Finally, you can look up the terms and brushes in the program's help files. They are quite good with examples and tutorials. Also, you have access to Lynda.com through your ANR Portal. Sign in and search for video tutorials on specific topics or specific versions of software.