I'll second the use of Liquibase. Writing changeSets is simple, and it's very easy to bring a developer's fresh database up to speed by simply letting Liquibase apply all the changeSets in order.

We've found that maintaining a separate "changelog" file for each major release that collects the history of changes for that release and subsequent minor releases is easiest. We also use the Jira ticket # associated with a schema change as the ID of a changeSet, so we can tie changes to feature requests, bug reports, etc.