Don't waste time. The end of the calendar year is almost here. If you have money in a regular Individual Retirement Account, get The Roth Revolution: Pay Taxes Once and Never Again and read it. This is the most complete and easy to understand book on Roth IRA conversions that I have ever read.
The author, James Lang, was the first person to ever write a peer reviewed article on Roth conversions. He provides plenty of tables, charts, and graphs to make this topic easy to comprehend. He also includes several real life stories involving Roth IRAs. He covers how to measure the benefits of a conversion, why you may not want to convert your entire IRA, how much you should convert, and the risks and pitfalls of a Roth IRA conversion. Probably one of the most important sections in the book is 'What if you Don't have the Money to Pay the Tax on the Conversion Outside the IRA'. He even gives specifics on what you should do depending on what tax bracket you are in.
Anyone who has an IRA and not a Roth IRA should read The Roth Revolution now.