I need to market to real estate related businesses but not directly to realtors or brokers. I need to Market to companies that have realtors and brokers as clients. What type of search Terms can I use using google?

real estate company
real estate companies
real estate management

Or you can even break it down to more specific target like adding your location.

Michigan real estate company

You should use keyword tools to check for keyword competition.

If you where a really astute marketer you would tell us what you are marketing and let it go viral.

Yes, please share with us what you want to market. Curious minds want to know.

Use Google AdWords...that's where you can see what people search for, and follow up by seeing what pops up when you type it into google.

That helped me narrow my market.

Google adwords keyword suggestion tool will be your best friend. If you have a general idea of what you think people should be searching for you can put it into the tool and it will show the number of searches made for that term. It will also suggest keywords for you to consider, these keywords will give you more keywords you could focus on.

Yes google adwords keyword tool is great or you can also try aaron wall's keyword suggestion tool: http://tools.seobook.com/keyword-tools/seobook/