US: Black Friday: It’s not just an important day for retailers — one that could bring in as much as US$42 billion — but it’s also an important day for bargain hunters across the country.

Meet 21-year old Sean Nguyen, of Myrtle Beach, South Carolina. For the past six years, he and his 10 closest buddies — the self-proclaimed ‘Black Friday Ninjas’ — have spent weeks mapping out their Plan of Attack…all for the Thrill of the Chase.

While the “Ninjas” primary objective these days is to make money in the secondary market (last year, they grossed $8,000), most Black Friday veterans are in it to save. These extreme shoppers include 21-year-old John Daggett of Branford, Connecticut, 30-year-old Amy Osterman of Altamont, Illinois and 54-year-old Micki Webb of LaPorte, Indiana. Here’s how they do it:

Research, research, research. To see what’s on sale, look beyond the circulars and head to designated Black Friday sites like Bargain Finders and Black Friday 2010. Compare prices on Shopping.com or PriceGrabber.com and read all the relevant product reviews on Eopinion.com, Amazon.com and others. Make sure you consider the extras. For example, the $399 HP laptop that Micki Webb plans to buy at Office Depot comes with a much-needed printer; the Xbox from Target comes with two gifts cards, worth $60 combined. “Other stores have the Xbox for the same price ($199), but instead of offering the gift cards as an incentive, they’re throwing in games that no one wants,” says Webb.

Divvy up responsibilities. Each of the Ninjas is responsible for getting all of the must-have items in their designated category — whether movies or digital cameras, for example. One person guards the cart, which is strategically parked near the checkout line.

Shop with a purpose. With as many as 200 million Americans expected to shop on Black Friday 2010, this is not the day to browse. “If you do, you’ll get trampled on,” Amy Osterman says. “Everyone becomes very aggressive on Black Friday, including me. I don’t let anyone get in my way.”

Put a value on your time. Although the pink rocking horse that Micki Webb saw advertised in the Toys “R” Us circular looks cute, she has decided against buying it. At $29.99, it’s only $20 off retail. And, she figures she’ll be in line two hours for it. “My time is worth more than $10 an hour,” she says.

Divide & Conquer. For the love of a $599 washer-dryer set — available at Sears to the first four customers — Amy Osterman not only moved the family dinner to Saturday so that she could be first in line at 3 p.m. on Thanksgiving day, but her husband will be nearby with the Nextel walkie-talkie, prepared to hit all of the other Sears within a 40-mile radius should her mission fail. “The set is our priority,” she says. “At 57 percent off, it’s like winning the lottery.”

Don’t forget the small stuff. Black Friday shoppers are so fixated on getting big ticket items, such as $299 flat-screen televisions, $90 e-book readers and $60 Blu-ray players that are hot this year, they often overlook everything else. “It’s a good time to load up on things like memory cards, flash drives, CDs and DVDs because they can be 50 percent off,” Sean Nguyen says. “People always think that if it’s not labeled ‘Doorbuster,’ it isn’t a good deal.”

Watch the clock. Limit your shopping to less than 20 minutes per store. Otherwise, you will face a checkout line that could exceed two hours, and you’ll miss out on the other Doorbusters, says John Daggett. He learned his lesson the hard way in 2008. After waiting inside a Circuit City for 30 minutes for an Xbox only to be told that there weren’t any, he spent the rest of his morning tracking one down in Milford, Connecticut, neglecting the other items on his list.

Get ticketed. Ever since the deadly Wal-Mart stampede in 2008, many retailers have been trying to make the experience more civilized by requiring tickets for Doorbusters. These vouchers, which grant consumers the ability to buy limited quantity items for a limited period of time, are handed out on a first-come, first-served basis — often just minutes before the doors open. While they do go fast, some are snagged by overzealous shoppers, and are never redeemed — particularly if there are no limits to the number of vouchers per person. This spells opportunity for latecomers, says Sean Nguyen. “At the end of the sale, check in with customer service and see if they’ll sell you any items that went unclaimed.”

Click and save. While pushing and shoving is a big part of the traditional Black Friday shopping experience, it’s no longer necessary. That’s because these days, 95 percent of the in-store deals are also available online — and in larger quantities, says Yung Trang, president of TechBargains.com. Plus, shipping is typically free and there’s often no sales tax. Yes, the tricky part is knowing when the sales go live. Check in early and often on BargainFinders or sign up to be alerted via text message or email.

If you want to attack the web like a Black Friday ninja this year, stay alert. Projected estimates suggest we’re not waiting around for Cyber Monday: Black Friday online sales are expected to jump from $595 million to $1 billion this year.