One of the biggest problems encountered on the web is the misuse of color.
I would recommend leaving photoshop for the help, and go straight to your
local community college or bookstore in search of color theory courses or
text. I would also recommend picking up a color set (pantone) and start
practicing. Cover the material in the collor theory class and begin to find
completments of colors found in print journals, on the web and so on.
Slowly you will become more adept at choosing the perfect matches of colors.
For example, try identifying colors in product lines, such as cars, or
furniture (ethan allan country), these all have a set scheme for color and
are often complementary. Create projects for yourself and then slowly move
this to the computer, many artists have difficulty making the transition
from the real life to the screen, so try some web-browsing of sites as well.
Hope this helps.
> I have a lot of trouble knowing what is a good complementary color to use
> with an existing color. For instance, say I have a background that's a
> shade of yellow and I want to create text of a color that goes well with
> that yellow background.
> What techniques can be used in Photoshop (or with any other product) to
> good matching colors for someone like me who doesn't have an inate sense