Tom Demers explains how to "attack a niche" for those just getting started. After selecting a niche, identify the best keywords. Demers walks you through four steps for choosing and optimizing keywords. He writes that once you have invested time and energy into identifying the best keyword opportunities, keep an eye on how they perform.
"The fact that any keyword tool (even ours) tells you a keyword is important doesn't mean you'll be able to rank for it, and certainly doesn't mean you'll be able to convert the traffic it sends," he writes.