If you’re serious about making a success of blogging, you need a keyword research tool like this. Such tools can also prove useful before you even begin. If you have several ideas, you can do your research up-front, and see which niche gives you the most chance of success, and which is already highly competitive. Working this out can save you an awful lot of time and money in the long run.

I think people's aresenal of keyword research tools are mostly the same: 1) You need a tool to examine search volume, most likely Google Keyword Planner 2) A tool to help you generate more keyword ideas. Tools that work with the search engines' autosuggestions are very popular such as KeywordTool.io and Ubersuggest 3) Then people might add a tool broaden the depth of their data, maybe including something like Google Trends or Moz's Keyword Difficulty tool.
Customize the data that LTP is going to fetch with pre-filters like “Suggested Bid” (or Cost per Click [CPC], i.e. the amount of money an advertiser is willing to pay for a click on their AdWords ad that is targeting that specific keyword), “Local Search Volume” (average number of monthly searches for a specific keyword), “Advertiser Competition” (the amount of advertisers competing for a specific keyword) and “Number (of) Words” (very important when you’re trying to find long-tail keywords).

Can't go wrong with the Google Keyword tool, SEMRush and Google Trends. The Keyword tool for volume estimates, SEMRush to see what keywords competitors are ranking for/targeting, and Google Trends to make sure the traffic is actually coming from countries I'm trying to target. Gives a relatively accurate picture of when to expect traffic spikes and seasonality insight.

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).