A document can be locked for editing (checked out) directly in the document editing interface, using just one click. After editing, another single click is all that's needed to check the document back in and make it available to other users.
Integration with Workflow
Content locking can be enabled globally or it can be used just with a particular workflow, where it is only enabled for documents in its workflow scope.
Adding Comments and Setting Version Number
When a content editor finishes their content editing and wants to check the document back in, she can also:
set a custom number for the new version, regardless of the previous version numbers
leave a comment with the version for other users to know what changes were made