Visit Admin > Catalog (tab) > Fields.

Click on the Action button on the top right corner of the product page, and then click over the Field tab as shown here.

Here you can edit or setup product fields.

You can see more field option on moving towards right.

Description of the fields.

Name: Here you can input the name of the product field that you want to have to help classify your products (e.g., condition, size, color, brand).

Pre-Value: you can input preset values for the product field.  If this field is blank, then you will be free to input any text here when editing a product, which is recommended in most cases, and especially for continuous values, such as size or weight. Only put data in the "Pre-Value" field if there is a certain list of applicable values that apply to the product field (refer to the screenshot below).

To save and finish, click Update Product Fields, which is located on the bottom left of the page.