Basic Flow of a Performance Test, as I've done them, for those interested:
1) Use The Grinder's TCPProxy to record a series of user stories, making sure to put in comments as you record
2) Trim down the scripts to only issue the necessary commands, delete the sleep times
3) Put in some text handling and error checking into the scripts to make things like searches into variable-based scripts, and custom site error responses (such as login redirects) into Grinder errors