I am considering starting an ad-driven website. I'll probably start with Google AdWords. (Is there a better alternative?) What is the "typical" amount a website can earn per click or per impression? I understand that there are many factors involved but I'm looking for a ballpark.
With such detailed information about the site your range is very simple: from $0 to infinity (well, the high end of PPC and CPM is in $50-100 range). This is because you need lots of traffic to bring any revenue off clicks and prices per 1k views start at just a few cents, but you still need traffic to generate views.
There is no average unless you are talking about a particular topic where you can research the keywords and figure out some of the numbers.
If you want to learn about other ways of generating ad revenue, I suggest you read this series by Darren Herman.