Paul Randall has a compiled document with all his blog posts on SQL Myths that I think is a must read if you consider SQL Server part of your core competence. It is probably not very interesting to pure devs, but I would still suggest you take a scan of this so you can avoid making assumptions that are either out of date or just plain wrong. Find the link to the PDF here: http://www.sqlskills.com/blogs/paul/CommonSQLServerMyths.pdf