Investors have it hard enough trying to make sense of the seemingly daily gloom-and-doom headlines coming from Europe. For new and experienced investors alike, though, The Motley Fool is here to answer your questions.

Last week, we put out a call for your investing questions via Facebook and Twitter using the #AskAFool hashtag.

In the video below, I answer a question that came from Facebook: “When should I sell a stock?” My take? This is an incredibly complex question that books have been written about. But that doesn't mean there aren't a few rules of thumb to abide by to guide your buying and selling habits. One big reason to sell is if you've lost faith in the company you've invested with. Another is if you have a better idea for that money.

To submit a question of your own, find us on Facebook or Twitter via the #AskAFool hashtag.

We all would like to build long-term wealth and retire well. In our free report “3 Stocks That Will Help You Retire Rich,” we reveal some stocks that could help you as well as some winning wealth-building strategies. Click here to keep reading.