Starting to learn

Please let me know how these photos can be improved. I finally have some time and have started playing with my T1i. Am learning Lightroom as well. Thanks to all!!!

I don't like the first image - large brown muddy mass....

The second one - I like the idea - some people will disagree with me, but I'd have liked to see the nose in focus too.

The ocean liner - I think there is a slight issue with your horizon

After that - what do you want to show?

On the last one:
Dirty water = yuck... - clean that up a bit and maybe fix the overexposed sky a bit?

1: A strong glare bisects the dog's right eye. I found the glare to be distracting.

2: I agree with DetlecCM, and I like this one too. Some may be critical because the dog's nose is cut off, though.

3: There is a lot of empty space in the foreground. I would crop it to eliminate the empty water and eliminate the post in the foreground.

4: Nice image of a quaint water scene.

5: The boat in the right corner draws attention away from the main subject (the marina). Consider cropping it or removing it in Photoshop.