For most lists you are going to want some type of spreadsheet editor to read and edit.  Common editors would be Microsoft Excel, Google Sheets and LibreOffice.

This quick tutorial shows you how to use multiple filters to get the targeted list that you want.
How to merge / combine multiple CSV lists together.  This makes things much faster when it comes to cleaning your list than having to clean multiple lists.

CSV Merging tools
Online Merging Tool http://www.filesmerge.com/merge-csv-files
Online Merging Tool http://merge-csv.com/
Here’s how to do it in Command Prompt http://www.tomnash.eu/how-to-combine-multiple-csv-files-into-one-using-cmd/
CSV merge and split program http://blogs.perficient.com/microsoft/2011/06/csv-utility-to-split-or-combine-csv-files/

Cleaning your lists with Excel.  Quick instructions on how to remove duplicates, how to remove multiple rows that have information in a cell that you don’t want.