keyword research please help

All you need to analyze when looking at competition is the top 3 spots of the given keyword as this is where you should be aiming to rank.

You need to look at the page's PR, the PR of the backlinks pointing to the page, the anchor text used for the backlinks, the quality of content on the page, especially how relevant the content is to the keyword search (i.e. does it offer what the searcher will be looking for?). Is the site an authority in the niche?

What I would suggest if you're just starting is to aim for a keyword with very low competition even if it means very low searches, this would help you from a motivational perspective as well as being able to see what you need to do to outrank certain amounts of competition. For the first few months you shouldn't be trying to make money but instead, trying to learn how everything works and how to get traffic. There's always a way to monetize traffic. I would as far as to say, don't even put any ads or affiliate links on the site until you're getting a fair few visits per day. The goal is to get traffic.

Keyword research is all about finding keywords with high searches, low competition and some commercial value. That's the basic formula of finding quality keywords. Now this is a very broad question, so I recommend you to read this:

How To Do Keyword Research - The Beginners Guide to SEO

It is part of the "Beginners Guide To SEO" by SEOMoz. I'm sure you will find it worth reading.