how to do keyword research with optimized sites?

Hey guys,

I would like some assistance in keyword research and researching the optimized sites for those keywords.

Firstly, here's my criteria, when writing articles for certain keywords I want to dominate -

Keyword traffic - average from 1,000-10,000 searches/month
Optimized sites ("in quotes") for the keyword in Google - 1,000 - 7,500 on average.

e.g. In the dog training niche. The keyword - "security dog training" (2,900 searches/month average) and (Results 1 - 10 of about 5,930), so, 5,930 optimized sites.

I'd be happy to choose this keyword to work with.

But, what happens if I have a keyword like - "Train a dog to sit" (1,000 searches), but the optimized competition for this term in quotes is (11,300 optimized sites). Then, I say, I'll add "How to" on the beginning... "How to train a dog to sit" (7,670 optimized sites). This roughly matches my criteria that I believe I can dominate for. My question is, will I still get a majority of the traffic once I add words like "How To" onto the keywords which result in less site competition?

Even if choosing keywords with 10k searches/month and more, but adding "how to" words to narrow down the site competition, will this be a valid way of going?

I'm sure I have explained clearly, if not, let me know . This is an area, I just want to really clarify.

I look forward to your replies.

Thank you

Kiran