I actually don't use any keyword tools aside from Google Trends, but only rarely do I even use that. I try to talk to many of our target audience members (entrepreneurs) as I can. I attend events, I have phone calls, I sit next to them while working. Generally speaking, I think it's a waste of time to START with keyword tools instead of actual customers. Yes, you can target people in broad swaths and get a high level sense for what's interesting and trending, but at least in the case of our business at NextView Ventures, it's way more powerful to talk to actual "customers" you serve.
The “Starter” tier, with 1000 keyword lookups every 24 hours should be enough for anyone starting out in blogging – or even people who are quite established. It’s pleasing to see a product where they don’t seem to trick you into having to pay for a more expensive version. On the more negative side, I did feel that you’re nudged towards doing annual payment, with the monthly option kept slightly “hidden.”
In a nutshell, Long Tail Pro helps you quickly find keywords in bulk based on a seed keyword that you input. In addition to returning hundreds of related keywords, the tool also shows search volume (monthly search volume), advertiser bid, number of words, rank value, and my favorite Keyword Competitiveness (helps you judge the competition and keyword difficulty).