Try shooting on aperture priority mode if you want control over the DOF (Larger aperature (smaller f-stop number) = more DOF) and get to know your gear. Don't let people tell you that expensive gear = good photos. You gear is good enough to do very high quality photos - sure you wont be blowing them up to billboard size but for posting to the web and printing out non billboard size prints it will be more then enough.
I couldn't find anything really wrong with the photos that I looked at. The preview thumbnails look fuzzy but once I clicked the image to see it they looked fine.