How To Go About This

[eluser]Marcelo Kanzaki[/eluser]
When you're building a web application its a good idea to start coding with a minimal planning. Just the necessary.

Then, as you test and use the app, you'll get a better idea of what should be done differently in terms of code and design.

Should the images have the same size? Maybe. Or maybe not. See how they look when you have 30 rows to display. My opinion is that they should respect the original ratio. Go to Flickr, and Google's images search for inspiration.

Get it out there as soon as you can and let the users tell you what to do!