in spain, everyone waits to do any major shopping until mid-summer, when there is an entire month of sales, referred to as "rebajas." i believe that this is the only time of year when stores have sales, and it's a bit fun to engage in the madness of a whole month.
for the rest of us, there are lots of good sales and deals going on right now.
-pixie market is having a grand ole sale on their site. there are lots of cute dresses and rompers marked down to reasonable prices. some examples:
-oak is in the middle of its 30/40/50 sale, where the first week, all things are 30% off, then forty, and finally fifty.
-on yoox.com, there's an extra 10% on the fall/winter collection with code "YOOX8"
-shoes.com will give you 15% off your entire order with the code "JULYSAVE"