Setting up attributes & features

[BWT]

Hey guys,
I never used the attributes or feature part to configure a product however I recently need to do this and am a bit confuse on how it does. I played around with both but could not figure out how to complete my need for the product.

What i need to do it add an option for customers to choose from two different types of prints (paper or canvas) I have seen on other sites something similar ware as the other site had the option for selfinstall or we install as a drop down and this is what i would like to do for certin products. How is this done?

Any hlep would be great thanks!

oh yes one more thing i did create a group with attributes (Non color) and could not add then when i clicked "ADD" nothing happens?

UPDATE

Oh i see now i have to use the product generator to add the attributes to the product i want them on.
What i did was after creating my groups / attributes clicked on "product generate on the right side you can see my attributes then add by selecting right colum click add edit number of products and then click generate to finish it off.
after doing this i see it added the drop down options to my new product for the customer to chose from!

here is a wiki i found about attributes that may help others.
http://www.prestashop.com/wiki/Attributes_and_attribute_groups/