I'm a beginner but I'll try and give some specific advice on what to work on.
#1 - Too much of the flower is out of focus. Also try not to center your subject, it's a basic rule that you can break but with flowers and other simple subjects it usually looks better offset.
Here's a quick link to what I mean:
Rule of Thirds.
#2, #5, #6, #7 - All of these pictures are very soft. I think it's mostly due to motion blur from camera movement. Get more light on stuff like this and use a faster shutter speed, you'll also be able to lower your ISO down to 200 or 100 to ensure maximum image quality.
EDIT: actually it may just be a narrow depth of field. In that case, you'll have to be careful where you auto focus because the distance from that at which the photo goes soft will be very small.
#4 (the only other pic of flowers) - Exposure and focus are good here. I'd crop off some of what's on the left and top, just to clean it up and show off the pretty pink blossom a bit more. When taking shots like this, be aware of the background - stuff back there can be distracting (in this case, the glass edge of the table, wicker chair and vertical blinds) and take away from an image quite a bit.
The portraits..
#3 - the flash is kind of harsh here. It also looks underexposed even with the flash. It's pretty soft too, probably either from the child or the camera moving maybe after you locked in focus, hard to tell. I would have shot this with the camera held vertically, and maybe used some other lighting (at home you can get creative and not have to resort to flash). The expression is subjective, but I like eyes open - to each their own.
#8 - your best shot (in my opinion) hands down. It's a cute picture and those (wow they're long) pretty eyelashes are in perfect focus. Might have liked this in vertical too, horizontal squashes and widens the face a little... just being picky though.
Just my opinions, I hope others leave some detailed advice, dissenting or not. :thumbup: