I'm making a monocle and I want to know how to make the glass transparent, do I just need to make the texture transparent?

Thanks

Forgot it mention, I know nothing about Blender so the tutorial needs to cover the basics. Thanks.

Does anyone know of a good tutorial for making TF2 hats on YouTube. I have found one for the the importing and exporting using the new steampipe method but he only touches on the modelling in Blender and I was wondering if anyone know of or has made a good tutorial for the modelling part?
Thanks.