April is National Financial Literacy Month. To mark the occasion, MarketWatch will publish a series of “Financial Fitness” articles to help readers improve their fiscal health, and offer advice on how to save, invest and spend their money wisely. Read more here. Do you have the annual jitters about filing your taxes? If you want your tax return to go smoothly, experts advise filing online. The Internal Revenue Service’s backlog to process returns hovered at 2.17 million unprocessed individual returns at the end of March. That includes over half-a-million paper returns. You have been warned.