please : what is the best way to sell my softwares/scripts online ? what are the best website marketplaces for this purpose ?
There are many script directories like hotscripts. You just submit your scripts to the script directories to get more exposure.
If you sell scripts, maybe you can try the scripts section in this forum, http://forums.digitalpoint.com/forumdisplay.php?f=116. I don't know about software.
You can also make your own website like a WP hosted simple site and from there you can target and promote/market your applications to your target market. You can build a list of interested people with an optin option by offering a limited version of your software/scripts, and in that you can build a solid list of your target customers to whom you can then promote your future software/scripts etc.