This week, we had something for everyone. First up is a treat for rookie investors, but the next is for anyone who likes to save money. Rounding out the trio is a group effort to help investors size up greentech stocks.

The Stocks Shall Rise Again

The Fool welcomes all investors, even those who aren't yet sure what a stock is or why they might want to buy one. Robert Brokamp, editor of Motley Fool Rule Your Retirement, rolled out the welcome mat this week and offered first-rate thoughts for beginning investors.

"Let's take a look at the true nature of stocks, and the care and feeding they require so that your portfolio will survive," Robert writes. Doesn't he sound nice? "Stocks aren't made of recycled people (unlike the food in the 1973 movie Soylent Green), but the prices are determined by human beings," Robert writes. Doesn't he sound, umm, intriguing?

To make money, you need to buy stocks, then sell them to someone else for a higher price. Robert gives this advice: "If you think the U.S. economy -- and the world economy -- will be bigger and better a decade or two or three from now, own a piece of that growth by investing in stocks."

Click to the article for more from this very Foolish Fool.

Costco Books Its Day in Court

Do bargain-lovers care where Costco (Nasdaq: COST) gets the goods it sells?

Costco's sale of Omega Seamaster watches that it reportedly obtained from third-party sources instead of from Omega owner Swatch Group has landed it in Supreme Court. Amazon.com (Nasdaq: AMZN), Target (NYSE: TGT), and a retail trade association have lined up to support Costco in a case that could have far-reaching implications, Fool columnist Alyce Lomax tells us.

She lays out the issue like this: Costco's "cost-cutting behavior doesn't always go over well with luxury-goods providers, who need to protect their high-end brands by charging high-end prices."

Click to the article to join the discussion on who's in the right.

Roundtable: Green Investing Ideas for Earth Day

Fools like to put their heads together when looking for good stocks; Fool.com routinely publishes roundtables that bring together some of our experts. The topic this week was "businesses trying to make green by being green. ... [T]he ultimate payoff for picking green technology winners could be the stuff of legends."

The Fools discuss the prospects of Massachusetts-based lithium-ion battery company A123 Systems (Nasdaq: AONE) and the strides First Solar (Nasdaq: FSLR) is making, for example. They also throw in thoughts about government subsidies and premium pricing.

Click to the story to find out if your portfolio could stand a dose of cleantech.

Amazon is a Motley Fool Stock Advisor recommendation. First Solar is a Motley Fool Rule Breakers recommendation. The Fool owns shares of Costco, which is a Stock Advisor and a Motley Fool Inside Value pick.

Fool online editor Kris Eddy owns no shares of any stocks mentioned in this article. Try any of our investing newsletters free for 30 days. The Fool's disclosure policy has found a new place to dwell.