With some retailers beginning in-store deals a full day early, Black Friday is already well underway. Follow along for some of the best Black Friday deals from Office Depot and Costco on tablets, e-readers, laptops, and more electronics.

Office Depot

Office Depot's Black Friday sales may only last Friday and Saturday, but the retailer has packed a ton of savings into that short time span.

You'll find one of the best deals available on Google's Nexus 7 tablet at Office Depot; the retailer is offering the popular device for $20 off its normal price at $229.99. The deal is limited to one per customer and you will have to visit your local Office Depot because it is not available online.

The Nexus 7 packs 4.1 Jelly Bean right out of the box. The 7″ display is 1280 x 800 pixels and made of scratch-resistant Corning® glass. Powering the tablet is the nVidia Tegra 3 quad-core CPU clocked at 1.3 GHz with 1GB of RAM, and a 12-core GeForce GPU. It comes with a 1.2 MP front-facing camera (no rear shooter) and a 9.5 hour battery (4325 mAH).

While other stores are also selling the Samsung Galaxy Tab 2 7.0 tablet for $179.99, Office Depot has unique twist: In addition to the Galaxy Tab, you can also get a Samsung Series 3 laptop in a $469.98 bundle. The notebook features a 15.6-inch screen, dual-core Intel Pentium processor, 4GB of RAM, and 500GB hard drive. (It's also being offered by itself for $329.99.)

If you're more concerned with size, you can pay roughly the same price for a 9-inch tablet as for the Galaxy Tab 2 7.0; the Lenovo IdeaTab A2 with 16GB of storage will be $199.99. Or you can spend another $100 and grab the 10.1-inch Asus Transformer Pad TF300 with 32GB of storage for $299.99.

Office Depot is forced to sell Amazon Kindle Fire tablets at the same price as competing physical stores, so the company is also dangling an incentive to purchase at its locations: Office Depot is offering a $25 Visa gift card with the purchase of the second-generation Kindle Fire (non-HD version) for $159.99.

With special features like X-Ray, Immersion Reading, and Whispersync geared toward enhancing the reading experience, Amazon's Kindle Fire HD looks like one of the few devices to successfully blend tablets and e-readers.

Black Friday deals on Ultrabooks have been fairly scarce, but Office Depot has a 14-inch HP Envy model with Intel Core i3 Ivy Bridge processor, 4GB of RAM, 500GB hard drive, and 32GB SSD for $599.99. Other laptop sales include the 15.6-inch Lenovo G585 with AMD processor, 4GB of RAM, and 320GB hard drive for $279.99, and a Toshiba Satellite with 15.6-inch display, Intel Core i3 Ivy Bridge processor, 8GB of RAM, and 500GB hard drive for $399.99.

If you need a desktop instead, there's an HP with AMD E2 processor, 4GB of RAM, and 500GB for $259.99, or a Lenovo system with Core i3 Ivy Bridge CPU, 6GB CPU, and 1TB hard drive for just $369.99. If an all-in-one model is more your taste, check out the 23-inch HP Pavilion equipped with AMD A6-series processor, 6GB of RAM, and 1TB hard drive for $479.99.

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.