This article is part of our "Best Stocks for 2011" series where our Foolish writers pick their top stocks ideas for the year ahead. Click here to see a review of last year's picks and our 12 recommendations for the year ahead.

Most economists see the economy improving next year and pesky unemployment rates finally turning the corner.

You don't have to wait, though.

China is booming already, and there's a great way to play the country's expanding economy through 51job (Nasdaq: JOBS).

Hire growth for higher growth
51job got its start by contracting with local newspapers to have its city-specific "51job Weekly" employment listings wedged into the paper. These days, it's the company's high-margin online-recruitment services bringing in more than half of its revenue. In fact, it's actually cutting back with fewer print editions -- now down to just 16 city-specific missives, compared to more than two dozen two years ago -- and 51job is still growing aggressively.

The shift to higher margin online revenue is paying off. Revenue climbed 24% in its latest quarter, but earnings soared 75%.

The network effect that propelled eBay (Nasdaq: EBAY) to greatness a decade ago -- as sellers went where the buyers went and buyers went where the sellers went -- is in full effect here. Job seekers flock to the 51job site because it's where the employers are -- and vice versa. There are now 142,098 employers listing their job openings through the online recruiting website, 56% more than a year ago.

51job isn't alone. China Career Builder and Monster's (NYSE: MWW) partly owned ChinaHR.com are all over this niche. Leading consumer auctions marketplace Taobao began offering free employment classifieds earlier this year.

It hasn't slowed 51job a lick. The site has established itself as the go-to place for serious job openings.

The appeal of 1.3 billion potential employees
China isn't just the world's most populous nation. The country's rapidly improving economy makes it fertile soil for investors.

How fast is China growing? Well, let's just say that it initiated an interest rate hike over the weekend to keep its heady growth in check. It's a problem that the rest of the world would love to have.  

I hear you, though. China is a volatile country with a restrictive government. Then again, that's also why I'm suggesting 51job over the faster growing Baidu (Nasdaq: BIDU) or a cheaper play such as online gaming specialist Perfect World (Nasdaq: PWRD).

There may very well come a time when China turns the screws even tighter on Baidu's search engine stronghold or clamps down on the youth trekking to Internet cafes to kill time in Perfect World's virtual multiplayer realm. Given Focus Media's (Nasdaq: FMCN) rampant collection of sponsor-backed video monitors in high-traffic areas, excessive commercialization can always come under fire. 51job, on the other hand, is just making it easier for someone with a job to fill to hook up with someone who is looking for work.

In that sense, 51job may be one of the less risky Web-based investments out there.

The value of 51job
On the surface, 51job isn't cheap. It is trading at more than 40 times trailing earnings, and nearly 30 times the $1.68 a share that analysts see the company earning in the year ahead.

Thankfully, 51job is growing a lot faster than even its heady multiples. Wall Street expects earnings to more than double to $1.22 a share in 2010, climbing another 38% in 2011.

The perfect storm of a booming economy that continues to create jobs and an Internet penetration rate that is still early in its run is too juicy to ignore.

China Xiniya Fashion (NYSE: XNY) went public last month largely on the premise that its emphasis on men's formal and business-casual apparel in second-tier cities will pay off given the emerging workforce in smaller cities. I like the theory, but 51job adds the chunky margins of cyberspace and the broader wingspan of China as a whole.

As far as years go, 2010 was very good for 51job and its investors. The shares have doubled since I recommended them to Rule Breakers subscribers this summer. There's no reason to believe that 2011 won't be even better.

Which is the best stock for 2011? See all 12 candidates here.