<p>Looks like my data warehouse project is moving to Teradata next year (from SQL Server 2005).</p>

<p>I'm looking for resources about best practices on Teradata - from limitations of its SQL dialect to idioms and conventions for getting queries to perform well - particularly if they highlight things which are significantly different from SQL Server 2005.  Specifically tips similar to those found in <a href="https://rads.stackoverflow.com/amzn/click/com/0596008945" rel="noreferrer" rel="nofollow noreferrer">The Art of SQL</a> (which is more Oracle-focused).</p>

<p>My business processes are currently in T-SQL stored procedures and rely fairly heavily on SQL Server 2005 features like PIVOT, UNPIVOT, and Common Table Expressions to produce about 27m rows of output a month from a 4TB data warehouse.</p>

Top of the list on a Google search for "Teradata Best Practices" gave me
TERADATA ADVISORY GROUP SETS BEST PRACTICES FOR BUSINESS OBJECTS AND TERADATA CUSTOMERS
EDIT
: Seeing as that's just advertising, as you've pointed out, see how you go with these. Please bear in mind that I don't have a clue what Teradata is and can't see myself using it any time this side of the 22nd century AD.
Teradata Discussion Forums
Best Practices for Teradata Deployments
Best Study Guides For  NCR Teradata Certifications
The middle one looks promising with it's nice long link tree at the top
Oracle® Business Intelligence Applications Installation and Configuration Guide > Preinstallation and Predeployment Considerations for Oracle BI Applications > Teradata-Specific Database Guidelines for Oracle Business Analytics Warehouse >
and the first link, to the forums, should put you in touch with the right people.