Fools were out and about this week in an investing world jampacked with actions and ideas. Here are three articles you might find useful as you decide how to invest your money.

Energy Stocks Post-Japan: 3 to Avoid, 3 to Watch
"Not all energy crises are created equal." Ponder that nugget from Motley Fool Hidden Gems co-advisor Seth Jayson for a moment, and then come back to the screen for the names of three smaller energy players where Seth sees significant opportunities.

Seth lays out the case for considering EnergySolutions (NYSE: ES), EnerNOC (Nasdaq: ENOC), and First Solar (Nasdaq: FSLR). But he notes that these are longer-term plays and that "investors shouldn't expect the same kind of reversal that rewarded opportunistic buyers of depressed oil patch stocks last summer."

See the article to read more about why Seth sees promise in each of these stocks and to find out which three related companies he thinks you should avoid.

5 Stocks That Are Cheaper Than You Think
Fool contributor Rick Munarriz pulled together the 2011 and 2012 estimated price-to-earnings ratios of five "presumably pricey" stocks that might be better deals than a glance would indicate. "These investments are high-beta growth stocks and will likely remain that way for several more years," wrote Rick, a member of the Motley Fool Rule Breakers team. "The key here, though, is that they aren't as expensive as pundits make them out to be."

SandRidge Energy (NYSE: SD), for instance, is valued at a big 62 times this year's projected net income, but it becomes a "head-turning bargain" with a growth spurt expected to put it at just 24 times next year's bottom-line target.

Read the article to see why Rick included the other four stocks on his list, which include Las Vegas Sands (NYSE: LVS) and Ford (NYSE: F). And click on the plus sign next to each ticker to put the stock on your free, personalized watchlist, which will keep you up to date on the stocks.

Rising Stars: Time to Buy More lululemon
Despite never having been to a yoga class, Motley Fool analyst Rex Moore is attuned to the promise of yoga-inspired retailer lululemon athletica (Nasdaq: LULU). This week he bought additional shares of it for his "multivitamin" portfolio, one of 16 real-money Rising Star portfolios that investors can follow at the Fool. Rex uses rigorous screening and fundamental analysis in his pursuit of a portfolio that's well-balanced and diversified across size, style, geography, and industry.

He checked out lululemon's fourth-quarter results, and in his words, "The biggest takeaway for me was inventory -- or rather the lack of it. The company couldn't keep product on the shelves." Check out the article to see the four growth catalysts Rex is watching at lululemon and to see what else makes this stock a buy for his multivitamin portfolio. Add lululemon to your free, personalized watchlist to keep track of the Foolish news and numbers.

See a stock in this story you'd like to follow? Add it to your free, personalized My Watchlist, which will find all of our Foolish news and numbers on the stock.

Fool online editor Kris Eddy owns no shares of any stocks mentioned in this article.

EnerNOC, First Solar, and lululemon athletica are Motley Fool Rule Breakers selections. Ford is a Motley Fool Stock Advisor pick. The Fool owns shares of EnerNOC, EnergySolutions, Ford, and lululemon athletica. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.