Included below is your free copy of the May 2009 issue of The Kitces Report on "To Roth Or Not To Roth". For a shortened version, see here for "Factors That Determine Whether A Roth Or Traditional IRA Is Better".
For further reading on this topic, see:
"How To Do A Backdoor Roth IRA Contribution (Safely)"
"Understanding the Two 5-Year Rules For Roth IRA Contributions And Conversions"
"Why A Roth Conversion May Be A Bad Idea Even If Taxes Are Higher In The Future"
"IRS Notice 2014-54 Acquiesces On Splitting After-Tax 401(k) Contributions For Roth Conversion"
"When A Roth IRA May Actually Be A Terrible Asset To Inherit"
"In-Plan Roth 401(k) Rollover Conversion Guidance Issued by IRS"