Custom template - how to integrate my html

Hi,

I want to make ecommerce site with my own template. I could implement master page with my own style of CSS/Html for top menus. I dont see a lot clear tutorials or guide on how to integrate my own design for registration page, login page, product page. 

Can anyone please provide me tutorial/ guideline or link on how to get implement my own design for pages like registration, login , forgot password, product etc.

Thanks