Seems an old question. But I never really thought about it well before, so here is one answer:
Once activated,The Publishing Infrastructure provides you, at the site collection level, with a number of document libraries, lists, Web Parts, additional administrative links and SharePoint Groups.
- Site Collection Documents: You should use this system library to store documents that will be used throughout the site collection.
- Site Collection Images: You should store images in this document library that are used throughout the site collection.
- Style Library: You should use this document library to store custom XSL styles and cascading style sheets.
- Content and Structure Reports list: This list contains the queries that appear under the Reports second level menu of the extended Site Actions menu in a publishing site.
- Reusable Content list: This list is used in publishing sites.
- Workflow tasks list: Configure Workflows to use this tasks list. This list, as are the other lists, are created in the root-site of a site collection. Of the three this is one that you could use, but as it's only created at the root-level of a site collection, you would have to manually create a Workflow tasks list for that site to maintain a consistent approach to using Workflows.
Activating the SharePoint Server Publishing Infrastructure feature adds the Administrative links on the Site Settings page, including the ability to manage Master Pages for both publishing and non-publishing Web sites, Navigation, Searchable columns, Content and Structure, Content and Structure Logs, Variations and Translatable columns.
Content Types and Site Columns
The Page Layout and Publishing content types and columns are added when you activate the SharePoint Server Publishing Infrastructure feature.
Activating the SharePoint Server Publishing Infrastructure feature adds the following Web Parts to the Web Part Gallery: Content Query Web Part (CQWP), Summary Links, Table of Content.
Activating the SharePoint Server Publishing Infrastructure feature adds the following SharePoint Groups: Approvers, Designers, Hierarchy Managers, Quick Deploy Users, Restricted Readers and Style Resource Readers.