Amateur looking for feedback

[newphotogirl]

So these are basically the first shots I've taken w/ my new (used) Nikon D80. I used a 50MM lens, basically just looking for some general feedback anything that looks good or what I could have done different to make it look better.

The 5th picture is actually from my point and shoot Canon SD100, using the Digital Macro setting.

The subject is my foster pug, I volunteer for a pug rescue and she is my current charge. I plan on shooting a lot of dogs and am wondering if the 50MM is the right kind of lens.

I am here to learn so thanks for any feedback you can provide.