newbie keyword research help

Hi all

I recently joined this forum and it seems like a decent place, so much useful information as SEO is something I am really lacking.

I'm a bit confused about how I should do my keyword research. I am using google keyword tool and looking at Exact searches. What is the realistic number I can try to optimize for without meeting serious competition?

Keyphrases that are close to what i want range from 1000 to 12000 exact searches

thanks