How to do a simple SELECT/UPDATE/DELETE performance test?
Simple down to 3ms accuracy:

SELECT GETDATE();
-- run query
SELECT GETDATE();


On SQL Server 2008 and above you can use SYSDATETIME() which has much greater accuracy.

You can also set a variable equal to the current time, run your query, and use DATEDIFF to determine the delta in whatever granularity makes sense (however this won't work across batches).

Other options:

SET STATISTICS TIME ON;
SET STATISTICS IO ON;


You can also look at the execution plans to determine where a specific query might have a bottleneck. I might recommend the free SentryOne Plan Explorer for this. If you generate actual plans from within the tool, it will show you actual runtime metrics for each query (everything shown above, without the work).