Now ... you should have made several Option Names like ...

Color
Size
etc.

And then set the Option Values for these like:
Red
Orange
Yellow
Green
Blue
Purple
Brown
Black
White

Small
Medium
Large
X-Large
X-Small

Using the Default Sort Order on these values will help you later in getting them into a nice display on the pages.

So now to add them to the products.

This is done via the Attributes Controller

You can look up a product in a couple ways ...

Either pick a Category or a Product

When you pick a category, the ones with a * have products in them and this will display the first product Previous/Next

When you pick a product hit display ... this sets the category to this products master category id ... so you can now use the Previous/Next if you like

Once the Product is displayed that you want to add attributes to ... go to the Add Attributes box

The Product Name should already be selected

Now select the Option Name

Next select a matching Option Value, notice they say what kind of Option Type you have selected

You will notice the Option Values say their names and next to them the Option Name that they match to.

Depending on what you want to do with attributes there are several methods to price, add weight, sort order, and mark the type of attribute this is.

Price can be entered with a prefix of + or - or blank

+ and blank will add the attribute price
- will subtract the attribute price

Weight can be entered optionally if it effects the product weight with a prefix of + or - or blank

+ and blank will add the attribute weight
- will subtract the attribute weight

There are other pricing options also available besides the standard prices.

One Time Charge
Price Factor
One Time Charge Price Factor
Attirbute Qty Price
One Time Attribute Qty Price

For TEXT
Price per word and free words
Price per letter and free letters

Then there are the Attrinbute Flags in the colored boxes.

These are used to help distinquish other features of the attribute such as:

Use for display only (attribute cannot be selected and added to cart. Good for things like "Select from Below" to force the customer to make their own choice and not just hit Add to Cart and get a pink snail instead of a blue snail :)

Attribute is Free when product is Free (Some products you may set to Free ... but the some attributes are free and some attriutes cost money)

Default Attribute (Should be used especially on Radio buttons, or if you have an attribute you prefer the customer selects.)

Apply Discounts used by Product Sale/Special (this will apply the same type of discount that the product is getting from the products_price vs the special or sale price)

Include in Base Price (when products are priced by attributes mark the attributes include in base price then the lowest price in each Option Name group are added together to make up the product price. NOTE: when not the product is not marked priced by attribute this setting has no effect on the price)

Attribute Required for TEXT (Some text is required text and cannot be left blank by the customer)

Be sure to hit Add to add the newly defined Attribute

You can always edit or delete them

When done ... you can update the sort orders for the product to the Option Value sort order by pressing the button at the top of the page.