1) Nice shot with a good use of negative space. The problem is that there are two subjects- IMO it would have been more effective if it was JUST the man walking or JUST the cyclist. Love the mood the picture creates though.
2) The flower should be in focus- that should be a priority when doing macro photography or close ups. I would also have used rule of thirds, it works well in a lot of photos and is important when doing shots like that.
3) Good photo, it's just a bit difficult to figure out exactly what's going on. The contrast between the white snow and darker shades is great, and makes for a good picture.
4) This one's really similar to 3, but I prefer this. The brook or stream or whatever it is takes up space well and provides some texture and action, and the snow in the top third adds some depth and interest.
5) Love his one. The green moss and the brown cave works well together, and the shadow and reflection make it a really interesting shot. The only downside is that the face of the rock is overexposed, but you might be able to fiddle around and fix that in Photoshop if you have it.
6) Love this one too- if the seagull was in focus (which it should be, as the subject) it would be even better (but I know how hard it is to focus on moving creatures!)
7) Great texture and the reflection off the sun makes it simple but beautiful.
So yea... Just a novice here but I know some stuff pertaining to composition and what makes a nice photo. I think you have some pretty good talent, good luck on the contest.