The iPad isn't entirely self-sufficient. These extra bits of gear can help.
A camera connection kit
Who said the iPad lacks an SD card slot or USB? Well, actually, it does, but there is a solution for you if you crave a physical camera connection. If you have an older pre-Lightning iPad, the two-part Camera Connection Kit ($29) offers two 30-pin dongles that work surprisingly well for owners of the original iPad, iPad 2, or third-gen iPad. One adapter accepts SD cards, the other has a USB port. Plug in a camera directly or pop in a memory card to import photos and movies to the iPad for viewing or editing, and sync them with a computer later. You can also experiment with some other surprising ways to use the USB connection with other devices.
If you're an owner of a new iPad with Lightning connectors released after October 2012, you have several choices: go with a separate Lightning to SD card or Lightning to USB camera adapter ($29 each), buy the Lightning to 30-pin adapter and use your original Camera connection kit, or look for a cheaper third-party solution. Either way, it helps to have one of these in your bag if you take a lot of photos...but, as cloud-based Wi-Fi uploading services have improved, and Apple's Photo Stream has made further strides, you might find it easier to import directly from the cloud.
More portable and more flexible than the Apple TV, Apple's HDMI connector comes in two versions: 30-pin ($39) or Lightning ($49), depending on which iPad you own. The adapter, while pricey, acts as a direct hookup for sharing videos or mirroring the iPad's display on a larger TV. Be warned, however: not all apps support HDMI output, so it's a little hit-or-miss. Just keep in mind that video data doesn't transmit over 30-pin-to-Lightning adapters if you're trying to connect to a different-model iPad.
The $99 Apple TV streams video well, but it really excels at being a wireless TV conduit for iOS devices: AirPlay video streaming of content, including home movies, streaming slideshows, mirroring of iPad content on a big screen, and even some games that turn the iPad and your HDTV into a two-screen experience. That, plus 1080p support, all make the Apple TV an excellent choice for a large home living room.
Thanks to the shift to Lightning connectors, iPads are now split between the world of 30-pin and Lightning accessories and charging cables. For iPads that are older, or for older accessories and chargers, Apple sells two versions of 30-pin-to-Lightning adapters: one a tiny plug ($29), the other a longer cable ($39). Both can be used for charging, syncing, and data transfers like SD card camera importing, but not for video output. Third parties are selling less expensive options on sites on Amazon, thankfully, because $30 and $40 is a lot to pay for a dongle...but we haven't vetted those out here yet. You only need one of these if you have older iPad accessories you don't want to part with. For many, getting a Lightning-to-Micro-USB adapter ($19) might make a lot more sense.
Living with an iPad as a laptop replacement and go-everywhere device means having a nice bag to carry it around in. A backpack can do fine, but why not go smaller? One of my favorites is the Tom Bihn Ristretto for iPad ($135), a rugged nylon bag that holds plenty of gear in its main compartment, and has an extra zippered front pocket for smaller accessories.
There are plenty of good and compact wireless speakers that work very well over Bluetooth or AirPlay, and you'll probably want one to turn the iPad into a little home stereo system. Two recent favorites are the Jawbone Mini Jambox and the Bose SoundLink Mini. Each costs under $200.
Are you a big on-the-go typist? Have you fantasized about making your iPad your little writing tablet? Getting a keyboard case can be a lot of fun, and even be quite useful, as long as you're looking for a tool to do pure writing versus heavy editing: none of the keyboard accessories made for iPads has a trackpad. The Belkin Qode Ultimate Keyboard Case ($129) is one of our early favorites for the iPad Air, improving on the previous design with a slimmed-down profile. It still has several different angles that snap in place with magnets, and it autoconnects and disconnects when not used.
Versatile, functional, great keyboard: I've liked Logitech's thin keyboard cover for years, and the newest version for iPad Air ($99) is just as good. It isn't a case, but it has magnets to stick on like a Smart Cover, and transforms into a seamless and comfortable keyboard when placed on a desk. If you have an iPad 2 or third/fourth-gen iPad with Retina Display, try the original Logitech Ultrathin Keyboard Cover ($99).
Some writers might want to look into a simple Bluetooth keyboard to pair with the iPad rather than choose a keyboard case; they're more flexible, less bulky, and often don't cost as much...and they'll work with any model of iPad. Apple's own Bluetooth keyboard is excellent, or you could use the Logitech Tablet Keyboard, which has a slipcase that transforms into a useful iPad stand, which will work with any iPad from the original to the Mini the Air. There are plenty of other options to choose from, and you probably have one lying around your home.
The iPad begs for a good case, but your decision may vary between the larger iPad and the Mini. For the full-size iPad, it might be tempting and fun to use the clever Smart Cover to keep the iPad's screen shielded, but the back will still be vulnerable. Look for a good snap-on back shield that's Smart Cover-compatible. Apple's Smart Case tries to solve the problem by making a standard folio case with a physically attached cover. The new version for iPad Airs, in leather, costs more ($69) but fits better.
A capacitive stylus isn't technically necessary (you could always use your fingers), but for sketch artists and extensive annotators, a good stylus is indispensable. Adding a pen to that stylus? Even better. The Wacom Bamboo Stylus duo ($39) adds a ballpoint pen and extends the barrel length of the already excellent original Bamboo Stylus ($29). A well-weighted, comfortable feel and a rubberized stylus tip are worth the investment, and the pen means one fewer item in your bag.
Now, what if your pen/stylus could draw in a notebook, and automatically have whatever's written in that notebook sync magically to an iOS app? LiveScribe 3 does that, via a combination of Bluetooth and a proprietary set of special notebooks made to work with the pen. It's not a cheap accessory ($149 for the pen, a notebook, and an extra ink cartridge), but I haven't seen anything like it for hard-core handwritten note-takers who want to cross-sync to an iPad. You can also record audio "pencasts" via the app that time-sync with notes you're taking. Trust me, it's impressive.
If you want a capacitive stylus with a little something extra, the clever Pencil uses Bluetooth to add a few extra features: a digital eraser on the back, and the ability to reject your palm and use your fingers to smudge digital ink in the compatible Paper app while the stylus is used to draw. Fifty dollars ($60 for the fancy wooden version as opposed to the graphite model pictured) is a lot, but when you consider that it unlocks extra purchases in the award-winning Paper drawing app that's cross-designed to work with it, it just might be worth it for an iPad sketch artist. Order one here.
The iPad has never had a very good built-in speaker, and unlike the iPhone or iPod Touch, it doesn't come with earbuds. For travel, or even everyday use, investing in a good pair of headphones is key. Apple's own EarPods are actually pretty great and inexpensive, but I'm also partial to the Etymotic hf2, which has excellent range and a built-in microphone (you'll want one of those for FaceTime, Skype, or taking dictation), but another longtime CNET favorite is the Klipsch Image S4i II (pictured above). For other picks, check out CNET's lists of the top headphones under $100 and under $50 (some don't include a microphone).