Profiler will help you determine what queries are being executed. You can use a trace along with the Index Tuning Wizard to get some suggestions on how to go about attacking performance issues. That'll get you started. From there you can start looking at the longest running queries (though admittedly quite a few people have posted that Profiler's times look more like a ballpark figure than a scientific measurement), figure out if you can optimize either by restructuring the query or adding indexes as appropriate.

K. Brian Kelley

http://www.truthsolutions.com/

Author: Start to Finish Guide to SQL Server Performance Monitoring

http://www.netimpress.com/shop/product.asp?ProductID=NI-SQL1