If your local library carries Publishers Weekly, you can see some listings of recent sales with $$ ranges for advances.
Actually a much better source is
Publishers Marketplace, which is an online service that costs $20 a month. There are dozens of new listings every day, in every genre, with the acquiring editor, imprint and agent listed, and ability to cross-check each of those names. Well worth it if you are actually interested in such matters -- though of course it will only give you the very vaguest idea of what dollar amounts were paid, since most people DON'T list $$ and if they do they do it in a very wide range, and anyway people can say whatever they want on there and it doesn't always reflect reality. And most people only list some of their deals.
(If you want to investigate, you might get your writing group to go in on a subscription together, since you can log in from any computer).
Publishers Weekly is a different kettle of fish altogether. As a weekly trade mag, PW is good for lots of things, but for quantity of deals listed, not so much. Pretty much the most important or unusual deals get listed there, but it is nowhere close to comprehensive.
To the original poster, who might have thought I was blowing him off, I'll be more specific: Good luck, but keep your day job. Even if you work as a shop clerk or a secretary or flipping burgers, you probably make more money per year than most authors do per book advance.
THIS IS NOT A GET-RICH-QUICK SCHEME, FOLKS.