If your area has a lot of competition it could be quite a challenge getting your site to rank number one on the keywords that have a lot of competition. I am just being honest with you.
In markets that have a lot of competition, especially if the market has a good profit potential, there are companies out there with full time staff to keep there pages ranked high in the search engines. And most of the time they cannot even stay at number one consistently.
Many of the sites that I manage are in highly competitive niches and I explain to my customers that we want to stay on page one of the search engines, sometimes we will hit the number one spot and sometimes we will not. But those sites take a tremendous amount of time and money to keep ranked that way.
It all depends on the competition and how much time and effort the competition is devoting to their SEO.
There are many good keyword research tools. Google has a good keyword planner, SERPS has a good keyword research tool. Just google keyword tools and you will find a whole list of them.
Honestly, the best thing to do is to run an AdWords campaign with a lot of phrase and broad match (using appropriate negative keywords or you will screw yourself) keywords. This will give you a ton of data on search volume (real search volume - not the BS volumes that tools give you) and what keywords actually convert into sales or leads for your site.