SO yes now you know that you need to have data in correct shape - but how to start all the juggernaut? I will tell you - this is a step by step process. So you need to identify your needs first. How to do that ? Profile your data using simple queries on database server like MS SQL server, Oracle etc. There are sophisticated tools available in the market who can profile data for you. What does this profiling meant to you - it analyze your data and will tell you how much dirty or incosnistent data you have. You may have some null values, date format issues, numeric and character data collision issues, binary data like male, female etc. Now once you know dirtiness of your data atleast you know where you stand. Now the next step is to analyze results and estimate the cleansing efforts. I will tell you that soon. Watch Out.
To get visibility of your data, Clean, Enrich, Classify Data - manage and optimize it better