Wedding photography is not for beginners. If they really, really want you, tell them you have to rent proper equipment and they are paying for it. You need to figure out what the environment is/will be, then plan accordingly. If shooting in a dark church, you need bodies that handle low light well, that is, high ISO with low noise, and you need really fast lenses — f/1.2, f/1.4, f/1.8. The challenge with those lenses is DOF. At f/1.2 it can be pretty thin. Focus is critical and it is best to set your auto-focus point on your subject and leave it there. Focus and recompose can be enough movement to get blur where it must be sharp. If the church is reasonably lit, you can use pro-grade zoom lenses — constant maximum aperture of f/2.8. A couple of stops slower than the primes but with Vibration Reduction they can work pretty well. You want one that is really wide, 16 mm on a full frame body. You want one that is moderately wide to moderately long, 24 or 28 mm to 70 or 80 mm, and you want a long one, 70 to 200 mm. The really wide one is not used a lot, switch it with one of the other two when needed, try to switch to the lens you expect to not need next. For this to work, you need two bodies. You also need spare memory and spare batteries. If you will be shooting outdoors and/or at the reception, you will need flash, at least one per body. Off camera flash is an option but may be too complex to bother with unless you have an assistant to keep track of gear and move things around for you. If you are indoors, you can point the flash straight up, rotate the head 90° and put a white card around the rear half as it sits on the camera. Hold the card on with an elastic. Cheaper and more effective than the light domes. You will need a couple of extra sets of batteries for each flash unless you also rent the external power packs, but then you are carrying extra weight around on your belt. Even after the photos are taken, there is a lot of post processing and someone has to deal with printing or laying out photo books. All areas worth learning, but I hope you can get out of being their photographer.
In 20130311-MelGrad, she has her shoulders too square to the camera. If possible, the light should have been 2 or 3 feet higher. The background is not doing you any favours.
In Grad Photo Japanese Gardens, firing a strobe would have put catch lights into their eyes. The light looks quite flat. That background is not doing you any favours, either. A faster lens and moving them from the background would cause it to blur. Adding flash would let you get a darker sky.
SumMelon, why the tilt? Why eating? It shows her hands pretty well!
Wind Surfing, was that taken with the mirror lens? Look at the difference between sky in the middle, and sky at the upper edges! You seem to have several spare kites in the photo too! And, all the water is running out of my monitor onto the floor. Rotate it without cropping, then clone in some sky and water before cropping.
The Jones, is suffering from a keystone effect. Better editors have a tool to straighten the image.
Red Raiders Reciever, needs a tighter crop. “Receiver” is the correct spelling. A portrait crop from the top, down to the bottom of his jersey should be enough to hold him and the ball, with almost nothing else. You should have enough pixels to do that, I think that would give a really good photo.
Untitled, could be called “Death with tulips”. The lighting is bad.
Gaze, needs levelling. What do you see in the photo that is compelling? Why should anyone look at it? What story does it tell?
OK, enough already. The planes and fish are pretty reasonable. The football player is your best photo, but it needs a tighter crop, and that team really needs to get numbers onto the shoulders of their jerseys.