i just now found this mod and i followed this guide to install it:
http://custom.simplemachines.org/mods/index.php?action=parse;mod=65;attach=179618;smf_version=2.0then i followed this,
Move the included directory "shop" to "./Sources".
Move the included file "shop.gif" to "./Themes/default/images/english".
Move the included file "Shop.english.php" to "./Themes/default/languages".
Move the included file "ShopAdmin.template.php" to "./Themes/default".
Move the included file "Shop.template.php" to "./Themes/default".
and i went to my forum and clicked on the shop link.but it came back saying there was a database error =\