Option for choosing a size in apparel estores

[Nimish]

I am setting up an online t shirt store and am unable to figure out how to allow my users to choose size.

[abolabo]

you should to set up product options for it. Start from menu Catalog->global attributes->add attribute->product option. Then assign that attribute to product  on edit page ->tab "options"

[Basara]

I am setting up an online t shirt store and am unable to figure out how to allow my users to choose size.

Hello. Read this documentation.