Hello,
I started photography about 4 months ago and I've been trying to learn as much as I can. I've only been able to do mostly landscape, still life, etc., however, I'm really wanting to do portraiture so I'm hoping I could get some advice & critiques concerning the job I've done.
Below, I've taken about 9 shots with a subject (embedded
only one, and I provided a link to the others since that's what the rules say).
I know that most of the problem in these is overexposure of the sky and one is pretty dark, but other than those two obvious things I would really love to hear other people's comments!

I am concerned about posing, post processing, composition, just the obvious things.
PS: Do these look sharp enough for you guys? So many portraits I see on studio's web sites are so extremely sharp I don't know if it has to do with their lens (I have a 28-90mm 5.6 kit lens

) or post processing techniques - anyone have a clue? I actually had to sharpen every one of these!
These pictures were taken with: Canon 400D with 28-90mm f/5.6 lens. EXIF data is below.
1.
http://i34.photobucket.com/albums/d1...t/IMG_9487.jpg
# Exposure Time = 1/2000 second
# Lens F-Number/F-Stop = F4.5
# Exposure Program = aperture priority (3)
# ISO Speed Ratings = 200
#Focal Length = 50 mm
2.
http://i34.photobucket.com/albums/d1...t/IMG_9557.jpg
# Exposure Time = 1/160 second
# Lens F-Number/F-Stop = F8
# Exposure Program = aperture priority (3)
# ISO Speed Ratings = 100
#Focal Length = 62 mm
3.
http://i34.photobucket.com/albums/d1...t/IMG_9550.jpg
# Exposure Time = 1/20 second
# Lens F-Number/F-Stop = F4.5
# Exposure Program = aperture priority (3)
# ISO Speed Ratings = 100
#Focal Length = 47mm
4.
http://i34.photobucket.com/albums/d1...t/IMG_9497.jpg
# Exposure Time = 1/400 second
# Lens F-Number/F-Stop = F5
# Exposure Program = aperture priority (3)
# ISO Speed Ratings = 200
#Focal Length = 65mm
5.
http://i34.photobucket.com/albums/d1...t/IMG_9495.jpg
# Exposure Time = 1/400second
# Lens F-Number/F-Stop = F5
# Exposure Program = aperture priority (3)
# ISO Speed Ratings = 200
#Focal Length = 64 mm
6.
http://i34.photobucket.com/albums/d1...t/IMG_9486.jpg
# Exposure Time = 1/1600 second
# Lens F-Number/F-Stop = F5
# Exposure Program = aperture priority (3)
# ISO Speed Ratings = 200
#Focal Length = 64mm
7.
http://i34.photobucket.com/albums/d1...t/IMG_9469.jpg
# Exposure Time = 1/100 second
# Lens F-Number/F-Stop = F4.5
# Exposure Program = aperture priority (3)
# ISO Speed Ratings = 200
#Focal Length = 35 mm
8.
http://i34.photobucket.com/albums/d1...t/IMG_9463.jpg
# Exposure Time = 1/160 second
# Lens F-Number/F-Stop = F5.6
# Exposure Program = aperture priority (3)
# ISO Speed Ratings = 200
#Focal Length = 41 mm
9.
http://i34.photobucket.com/albums/d1...t/IMG_9461.jpg
# Exposure Time = 1/100second
# Lens F-Number/F-Stop = F5.6
# Exposure Program = aperture priority (3)
# ISO Speed Ratings = 200
#Focal Length = 64mm
Thanks so much I hope I get to learn a lot to improve on my skills! Goodnight