Obviuosly try out the free tools provided.
But if you are looking for in-depth analysis of your keywords and the likes, I recommend KeywordDiscovery.
www.keyworddiscovery.com
Excellent tool imo. Has a few neat features that would be pretty useful to anyone. I especially like the history span of the keywords which goes as far as a year. With this, you can gauge the trends of your niche, and perhaps predict when the trend will start again and build your project accordingly.