Hi there, read the god delusion, it was very enlightening and took me from agnosticism to mostly atheism - thank you! Sincerely, thank you very much.
One thing you could point to as solid proof for natural selection however, is our best and most beloved friends, dogs. They are mostly today hybrids bred by us to produce different breeds for different purposes. For me, given time and inter breeding in nature, this could have happened naturally and is solid evidence of mans (human rather, ok:) ability to use nature to our own advantage.