This tutorial covers all templates included in SharePoint with a description of it's functionality and possible ways to do certain tasks or to enhance it.
Each template is categorized by the SharePoint version it's included and by the template category. For example SharePoint Foundation 2010 includes the Team Site template which belongs to the collaboration template group.
Of course this template and template group is also included in Search Server as well as SharePoint Server Standard and Enterprise.
Although SharePoint itself offers a lot of templates it's only a basic starting point for you and your customers since each company has its own requirements. Because of the diversity it's not possible to create a template meeting everyones requirements.
Anyway if you take a look at the templates you will see what you can do and how you can do it.
This site will be continually updated with new SharePoint templates.
SharePoint Foundation 2010 Templates
Search Server 2010 (Express) Templates
Search Server 2010 and Search Server 2010 Express have the SharePoint Foundation 2010 templates and additionally:
SharePoint Server 2010 Standard Templates
SharePoint Foundation templates are also available in Sharepoint Server 2010 but may be enhanced with additional functionality. Furthermore SharePoint Server 2010 - Standard has the following site templates:
SharePoint Server 2010 Enterprise Templates
SharePoint Server 2010 - Enterprise has the templates of SharePoint Server 2010 - Standard and additionally the following: