I'm sure this is simple, but I am confused to how to do this.
 
For most of my products there are 2 sizing options - either they are S-2XL or S-3XL
 
The first set of sizing options is; Small, Medium, Large, XLarge, & XXLarge. The second set includes the previous plus "XXXLarge".
 
How & where can add these 2 option sets and then call them for a product rather than having to add these to each product.
 
Thanks,
Confused!

You can do this by assigning the options to the product type instead of the product itself. Right now, all your items are probably of type "Product". ViArt comes with "Product", "Bundle", and "Accessory" as default types I think.
If you create two new product types, and then add the two different sets of size options to the product types, then change your individual products to use the new types instead of the default one, you will get what you want.
We do this now on our site. It also makes changing options and prices much easier.

Thanks. That's what I was looking for.