This is a built-in function of zencart... no need to install modules.
The first thing you must do is sit with a piece of paper and write down all the product variables that will apply in your business.
Divide the paper into two cloumns.
In the left column write down all the Features a product will have.
In the right column, write down all the Variances for each Feature.
EG:
FEATURE . . . . . VARIABLES
Colour . . . . . . . . Red
. . . . . . . . . . . . . .Blue
. . . . . . . . . . . . . .Green
Size . . . . . . . . . Small
. . . . . . . . . . . . . Medium
. . . . . . . . . . . . . Large
When you are done, you need to use the OPTION NAMES MANAGER under the catalog/products menu, and create option names that match your list of FEATURES.
Then, you use the OPTION VALUES function to assign the VARIANCES for each FEATURE (Option Name).
Option Name . . . . Option Value
Colour . . . . . . . . Please make a selection...
. . . . . . . . . . . . . .Red
. . . . . . . . . . . . . .Blue
. . . . . . . . . . . . . .Green
Size . . . . . . . . . Please make a selection...
. . . . . . . . . . . . . Small
. . . . . . . . . . . . . Medium
. . . . . . . . . . . . . Large
NOTICE THAT I have created option values called "Please make a selection..." for each of the Option Names. (reason why will be obvious later).
To start, make these TYPE = DROPDOWN selections.
Now... you need to asign SORT ORDERS to these as you create them. There is a little field for you to enter a numerical value...
Option Name . . . . Option Value
Colour . . . . . . . . Please make a selection... (ORDER = 1)
. . . . . . . . . . . . . .Red (ORDER = 10)
. . . . . . . . . . . . . .Blue (ORDER = 20)
. . . . . . . . . . . . . .Green (ORDER = 30)
Size . . . . . . . . . Please make a selection... (ORDER = 1)
. . . . . . . . . . . . . Small (ORDER = 10)
. . . . . . . . . . . . . Medium (ORDER = 20)
. . . . . . . . . . . . . Large (ORDER = 30)
When you have done the above, come back to this thread and let me know...