ive never used or heard of google web up until now (the first answer) so that sounds interesting, i'll take a look at that sometime this week me self ^_^
but imo - use Dreamweaver MX ^_^
or simply register with a hosting provider/domain registrar and purchase one of their web authoriing/website creation toolkits which will allow you to build robust, secure, professional looking e-commerce sites in no time.
you get to choose fround hundreds sometimes thousands of templates and its a drag n drop thing with these toolkits, you don't need to worry about the presentational side of things i.e the markup or the css , its all done automaticaly for you - just drag n drop placeholders, icons, images etc onto the screen and when youre done - - save and hit next etc etc
then publish and view on the web.
its better this way - BUT if youre like me and you like to do things from scratch cos of personal pride and wanting to be the best of the best , then hard code it all from scratch using notepad or any other web editor ^_^
i write my own css stylesheets and take pride in knowing that the WHOLE ENTIRE 'look' and 'feel' of the site itself is 100% original and my idea and mine alone.
just google up 'ecommerce site builder' or 'ecommerce website designer tools' and see what comes up.
theres got to be hundrds out there - btw have you heard of joomla and drupal ?
Drupal is the way to go man - everybody is using Drupal these days - but not meeee ! ^_^
lol