It should be under Site Collection Administration from what I've read, and I see it on my SP2010 Enterprise server. Does auditing not exist on SharePoint 2010 Foundation? This is my list at the top ...
Site Collection: Configure Audit Settings: Selected audited events only remain checked for a few minutes
Under Site Collection Administration -> Site Collection Audit Settings, I can enable events to audit, click OK. Then I go make changes; update a list item, delete a document, check out an item. I can ...