You can begin the 1st step of researching your keywords by simply looking at your competition and putting their site and a few of your industry's/niche's keywords into a tool called "Google Keyword Planner" which is a tool that every online marketer uses to start his searches on finding the best keywords. Now Google Keyword Planner (GKP for short) does not supply you with ACTUAL COMPETITION SCORES like we do - they only supply competition based on the fact that you would be doing PPC (Pay Per Click) with them.
So once you've gotten an idea on what the keywords being used are inside GKP - you can then move over to the next step. We often like to use MOZ ($100 / mo), Long Tail Pro Platinum ($100 + $20 / mo.) and if possibly Raven Tools ($100 / mo.).
While most of these tools are not available to you - and beginning to explain how to research and use them would just be us basically training you how to do our job... safe to say - our research always comes back with the most up to date and accurate stats and quotes on getting you ranked in a specific time frame + knowing the Top 10 Competitors for EVERY KEYWORD is a big bonus your competition probably does not have available to them.