Wordtracker's data is for 90 days, not 30 day(Check their website!). Only Wordze provides real time data for the last 30 days. yajunithish, You can see some of their videos on using the tool at wordze.com/videos/ and I have seen a handful of videos and tutorials around by other people on blogs, hit up GOOG to find them!
wordtracker is good but adwords keywoord tool is rubbish. What you need to do from adwords keyword tool is just to describe what you want for your keyword then you must find how many searchers from other keyword tools. Even if in adwords keyword tool the search volume is not low (average), but when you get in the 1st position of that keyword, you can't always get many traffic. I suggest wordtracker and also keyworddiscovery. Google trends might also help.