There are lots of ways to research keywords related to your niche. Google keyword tool & Wordtracker are the most popular tools to research keywords manually. For manual keyword research, I prefer wordtracker. Wordtracker has the least skewed search counts so I use that as a rough guide to find out how many people are actually searching for my keyword phrases. But to do the manual research is a tedious and time-consuming process. SEO tools dominates manual keyword research process in this case. These tools are generated in a way to output quick results for estimated keyword with detailed options. You can use a trial version to experience how these tools can help you.