Another handy tool provided by Microsoft. Here is the link to SQL2005 BPA.
Description from MS: The SQL Server 2005 Best Practices Analyzer (BPA) gathers data from Microsoft Windows and SQL Server configuration settings. BPA uses a predefined list of SQL Server 2005 recommendations and best practices to determine if there are potential issues in the database environment.
I have used this tool and it produces informative reports on the SQL installation. Some of the tips it can provide are on security settings, performance suggestions, etc based on the best practices. SQL BPA even reads the logs to check for past errors and informs the operator on whether the server looks faulty. Even suggestions on disk sector alignment, performance issue related to logging, etc is provided. Clicking on the rows will open up the help document related to the row clicked.