I also remember saying to you to turn off the setting which sets the ISO on auto and set your ISO manually to 100, when it is on auto it does silly things and can increase the grain.
If you can set the camera to manual exposure it is much better and where you can look at the histogram on the camera you can adjust your exposure to get the optimum exposure and post processing will be much simpler.
It's the aperture that you set to f5.9 not your depth of field although it is related. I would use a longer focal length that 24 in fact I think I use 105, but looking at your photos I wouldn't change anything as you are producing great photos.
I have got various photoshop books if you want them, but to be honest they might over complicate things for you.
A little tip that might not be of any use is that when you focus on something you have more depth behind the focal point than in front of it, so depending on your fstop and the focal length of the lens you are using, it is often beneficial to focus on a nearer part of the subject and you can get images that look sharp from front to back, of course everything has it's limits.
Peter
