Shopping Armageddon is almost upon us, are you prepared? Best Buy, Walmart, Staples, Kohl's and more have all already released or "leaked" their Black Friday shopping guides to the public. And the game only continues to heat up. Follow along below for great deals on tablets, laptop computers, HDTVs and more from Costco, Sears, and Kmart and check back often for more updates and new deals.

Costco

Costco's sales runs three days, but unlike many of the others we have seen, it's not running from Thanksgiving Day through Saturday, but instead from Black Friday, Nov. 23 through Sunday, Nov. 25.

Costco's Black Friday sale begins at the modest time of 9 a.m. Nov. 23.

Deals run the gamut from HDTVs, Android tablets, Blu-ray players, digital cameras, laptops, desktops, apparel, housewares, and more. The ad includes four pages of online-only savings, as well.

Some of the best in store offers on laptops include the Dell Inspirion 17R laptop PC with Windows 8, Intel Core i7 processor, 600x900 HD display, 8GB memory, 1TB hard drive for $799.99 ($150.00 off).

Costco is offering the highly-rated Samsung Galaxy Tab 2 10.1-inch tablet with Android 4.0, dual cameras, built-in IR blaster, 16GB, and 1GHz for $100 off, and the 7-inch version for $70 off.

Online only offers

HP dv7t 17.3-inch quad laptop with Intel Core i7 processor, 12GB memory, 1TB hard drive, backlit keyboard, Blu-ray writer for $999.99 ($400 off).

Dell Inspirion 15.6-inch 15R laptop with Intel Core i7 processor, 8GB memory, 1TB hard drive, wireless display and Bluetooth for $599.99.

Sears

Sears is offering some of the longest in store hours of any retailer during Black Friday weekend. Sears will be open all-night Thanksgiving starting at 8 p.m., which is also when its first set of Door Buster deals start. Friday's Door Buster deals start at 4 a.m.

Thanksgiving's best doorbuster deals:

A 32-inch Class HDTV for $97.

Toshiba 50-inch LED 1080p HDTV for $299.99.

A 6-inch 2GB Nook Simple Touch with WI-Fi for $39.99, or the X-Treme Tab 7-inch tablet with 2GB Micro SD, Android 4.0  $39.99.

Asus X401A 14-inch 2GB RAM, 320GB HD, laptop with DVD drive, Windows 8, Intel Celeron B830 processor for $174.

Friday's Door Buster deals:

The HP Pavilion G6 15.6-inch laptop with 4GB RAM, 320GB, Windows 8, AMD Dual Core A4 processor and Bluetooth for $299.99.

Mach Speech Trio Stealth 7-inch multi-touch tablet with 4GB, 1.2GHz, Micro-SD slot for expandable memory for $69.99.

4Sight 9-inch multi-touch tablet with Android 4.0, 4GB, 1.1GHz for $89.99.

Mach Speed Trio Stealth 9.7-inch multi-touch tablet with Android 4.0, 8GB, 1.2GHz, and Micro-SD expandable memory for $119.99.

Seiki 39-inch Class LCD 1080p HDTC for $199.99.

Major name brand 50-inch HDTV for $299.99

Available all three days:

Maylong 7-inch multi-touch tablet with Android 4.0, 8GB, 1.2GHz, and Micro-SD expandable memory keyboard case bundle $99.99.

Samsung Galaxy 7-inch tablet with Android 4.0, dual cameras, built-in IR blaster, 8GB, and 1GHz for $177.99.

Samsung Galaxy Tab 2 10.1-inch tablet with Android 4.0, dual cameras, built-in IR blaster, 16GB, and 1GHz for $297.99.

Kmart

Kmart will kick-off their Black Friday deals with the first round of doorbusters starting at 8:00 pm Thursday night, lasting until 3:00 am Friday morning. Then they will re-open at 5:00 am, featuring another round of doorbusters, and will remain open until 11:00 pm on Black Friday.

There will be some great sales going on during both rounds of doorbusters and throughout the weekend, but it looks like the steepest discounts reside in the 8:00 pm - 3:00 am timeslot. Here are some of our favorite items:

Proscan 50" 1080p LCD HDTV - $288 (reg: $699.99)

Panasonic DVD 5.1 Channel Home Theater System - $99.99 (reg: $149.99)

3 a.m. Door Buster deals:

Mach Speech Trio Stealth 7-inch multi-touch tablet with 4GB, 1.2GHz, Micro-SD slot for expandable memory for $69.99.

The HP Pavilion G6 15.6-inch laptop with 4GB RAM, 320GB, Windows 8, AMD Dual Core A4 processor and Bluetooth for $299.99.

All three days:

Up to 50 percent off select Craftsman tools 50 percent

Up to 80 percent off all fine jewelry

Samsung Galaxy 7-inch tablet with Android 4.0, dual cameras, built-in IR blaster, 8GB, and 1GHz for $177.99.

All LeapFrog LeapPad Ultra eBooks are buy one get one free; LEapPad 2 is $99.99; green or pink LeapPad1 for $64.99.

11 a.m. Door Buster:

Mach Speed Trio Stealth 9.7-inch multi-touch tablet with Android 4.0, 8GB, 1.2GHz, and Micro-SD expandable memory for $119.99.