hi everyone...
i need some help. ;-)

i picked up a copy of market samurai a while back and i'm trying to find some keywords. i'm working on creating blogs for several niches. i'm hoping to use a mix of amazon products and adsense to monetize the sites.

i think i have everything pretty much covered...but i'm just really confused on how to analyze data to determine good keywords. i keep hearing that "niche" and "keyword" selection is paramount, so i want to make sure i put a good process in place. (i.e. monthly exact searches > 10,000 and adword competition > 50)

does anyone recommend some quality places to learn good keyword selection?
(...or can anyone offer help themselves?)