I saw @parscale tweet: How many queries are you happy with for a home page? When do you say this is Optimized?
I saw responses that < 50 is good, 30 or less is best, and 100+ is danger zone. Is there really any proper number? And if say you do have > 50 queries running on your pages, what are some ways to bring it down?
I generally have sites that run the gamut that are under 50 queries and some more, though the "more" don't seem to be too slow, I'm always interested in making it faster. How?
How to reduce queries will vary from site to site, template to template, but there's been a few articles on EE optimisation and performance:
http://expressionengine.com/wiki/Reduce_Queries/
http://expressionengine.com/blog/entry/troubleshooting_site_performance_issues/
http://www.netmagazine.com/tutorials/optimise-your-expressionengine-site
http://www.leezilla.net/post/12377053779/ab-seeing-your-sites-performance
http://eeinsider.com/articles/using-cache-wisely-with-expressionengine/
But if you've done all that and still need to speed things up, then your next step is to look at add-ons like CE Cache.