You can start at DP for link exchange, if you have sites and looking for link exchange, there are webmasters who would respond to your request. You would need to put details about your site, traffic, rank etc For Google ranking - i am not sure about your question here.
These days less and less quality websites are open to link exchanges. You might have better luck by hitting up the link exchange directories...linkmarket, linkexchanged, etc. Also you can check the link partners of some of your competitors. You shouldn't put all your efforts into link exchanges though. Try to spread out your time to try some other strategies...forum signatures, blog commenting, article distribution, etc.