Thanks for recommending Organic shop. Any other suggestion please, Thanks
Just study and dissect existing themes and use them for learning purposes. For responsive themes I would look at Twenty Twelve, Bones, and Skeleton.
http://underscores.me (I use this)
Tutorials & Other Useful Sites
Thank you so much. Your advices are very valuable for me. Could you tell me some more about CSS and JS? Which is the best option for theme?
I found this. I think here is a good article for who’s beginning building a WP premium theme.