Ard, a wonderful shot to begin with. Tokengirl beat me to it with her fine edits. ( I was nervous to post mine after the recent thread on critiques here :-).
You were able to capture a background without (much) distraction, which often can ruin a great foreground. I would either darken or crop out the bright green at the left.
I like to shoot unposed portraits, especially children's. Sometimes I have to wait forever for the right expression. But just when the moment arrives, the parent would notice my presence and yelled, "Jimmy, smile at the camera." The moment would be gone, leaving me wanting to wring the parent's neck. At your subject's age, I suppose the child has not learned to pose yet. Keep shooting before he does, which will be sooner than you realize.
As Tokengirl noted, your second image is actually less sharp than the original. Compare the right eye lashes between the two. Tokengirl rescued that. The eyes' white is also darker in your second one. I would slightly lighten the eyes' white in her last edit. I would also clone out the two tiny white spots under the left nostril. These were not visible in the original, and might be the result of sharpening. One thing to remember is that during editing, make sure that improvement something is not at the expense of degrading something else. Often, that means applying a mask to isolate the correction to a certain area, or by cloning.
I have found that getting the "correct" skin tones is by far the most difficult part of editing. It took me years of editing landscapes, etc. before I gained sufficient skills and confidence in editing skin tones.
