Adding a size attribute

[gjh42]

You can hide a particular set of categories in the categories menu. See Howto: NOT list category on sidebox ? for an example.

[emilfalcon]

Thanks again!...Also, is it possible to set attributes to all the items in a certain category in one go without actually setting them 1 by 1 for each unique item?

[gjh42]

"Once you have this set up properly for one product, you can copy sets of attributes to others in bulk."
You may need to have one attribute in each product so the bulk copy feature can access it... check the available controls, and look in the FAQs for copy attribute.