Tad underexposed, and whats with the weird halo around the tree on the left. Looks like resizing did a number on this photo, artifacts galore (photobucket sucks!). I cant really make out any fine detail in the photo.
#1 is excellent. Maby a tad underexposed and some lost shadow detail. Good exposure is hard, I struggle with it myself. You should go back to location #2 and re shoot, could end up being a great picture.
Way way way way too many pictures to even begin to comment on any individually.
My only comment would be to watch the reflections. You have some good compositions that are completely ruined by whats reflected in that shiny paint.
I liked 23 (ignoring the blue folding chair) and 25
Some great shots. #1 and #3 are the best. For #2 and #4, what are you trying to show me, the subject is not so clear.
Tips to reduce bluryness... Ditch the night mode, its complete trash on the D40 and usually makes poor choices. At the least use Program, or Aperture priority so you can play...
If you are printing an 8x10 you need the number of pixels for the length and width to be a ratio of 8:10 after cropping. For a 4x6 you need 4:6, etc,etc. Any photo software should be able to manage this easily.
I see your working with CS3 so... When you go to the crop tool set the dimensions...
I can't imagine it would be too hard to make a pinhole camera. Think about whats in a regular film camera and distill it down to the very basics. You need a lightproof box, some way to hold and advance the film. A hole to allow light in, and a shutter to block the hole. Get yourself some...