Hi, Tanya ..
I like to use
http://www.Nichebot.com, which utilizes the free version of WordTracker ... and Google, to find related keywords.
This allows me to use keywords as sub directories that are relevent to the site topic, have reasonable popularity in regards to searches ... yet don't have as much competition.
The search engine spiders, for the most part, like relevent link text ... and this allows me to increase my exposure far beyond general terms ... while remaining relevent, thus increasing opportunities ... and conversions, by staying on topic.
A also like to use this tag analyzer, to optimize my head content:
http://www.submitexpress.com/analyzer/
I've enjoyed reasonable success researching, testing and tweaking the aforementioned ... taking into consideration the content relevence and incoming links, of course.
Regards,
Mike "great series, Tanya" Merz
PS
I'll add some link building tips as a follow up in a bit ..