On the Agile Database group the other day, there was a message that mentioned that their company provided a training course that included Liquibase.
Note: I know nothing about the course beyond the link above, but I know there has been interest in Liquibase training in the past and this may be a useful option for some.
I am mentioning it because it is the first professional Liquibase training I have seen, and also because of their quote on the group: “Run, don’t walk to liquibase.org and find out more about this lifesaver.”