Can anyone offer any software suggestions or best practices for QA'ing complex websites? To be specific, I have built and currently maintain a few sites, and I'm always paranoid about breaking something when I release a new version. Because of this, I've built a pretty solid development environment tied into svn. I feel like my planning, development, source control, etc. is about as rock solid as it will get.
However, when it comes time to release and QA, I have been unable to find a decent solution other than cumbersome excel spreadsheets loaded with lists of items to test.
I'm not sure what I'm looking for, but offhand, I think something to manage URLs and items to check on each URL would be a good start. Also, there are other obvious items I want to check, like http headers/404 errors, w3c validator, etc.
If anyone cares to share their QA methodology for website development, I would love to improve my less than stellar QA system.