A question that's asked by many is whether an iPad can function as a notebook replacement. It can, to a certain degree, but it largely depends on what your needs are.
An iPad can function as a notebook replacement for many things, and can do almost everything a full-blown computer can, like web browsing, word processing, multimedia playback, image editing, social networking, email and gaming. At the same time, its capabilities are fairly limited for each type of computing task, and for advanced tasks like video editing, 3D gaming, and complex word processing or spreadsheeting, you're better off with a proper notebook. Also, iOS can't display more than one app at a time, which makes it difficult if you need to view two or more windows side by side on a regular basis.
The keyboard case is handy for heavy typers.
But let's just say that your computing needs are fairly modest. The iPad can function as a versatile notebook replacement with the help of some extra hardware and apps. If you need to do a lot of typing, a Bluetooth keyboard is one of the best investments you can make for your iPad. The accessories market is crowded with a wide variety of iPad-compatible Bluetooth keyboards - from ones that are small enough to put in your pocket to full-sized keyboards that you can also use with a Bluetooth-equipped desktop computer. Our favourite is the Logitech Keyboard Case by ZAGG, as the keys have excellent tactile feedback, and it folds up into a compact, transportable package that protects the iPad's screen during travel.
Other accessories that are worthwhile getting include the Apple iPad Camera Connection Kit (for transferring photos from a digital camera or memory card) and the Apple Digital AV Adapter (for connecting the iPad to a HDTV or LCD monitor over a HDMI connection). For times when the iPad's 9.7in screen isn't quite big enough for your needs, the latter accessory in particular comes in handy for blowing up the display to a more comfortable size. If you have the new iPad or an iPad 2, the Digital AV Adapter can "mirror" the iPad's display on the external monitor, so that everything you see on the iPad is replicated. If you have an iPad 1, video mirroring isn't supported, but you can use the 'video out' function of core apps like Safari, Photos, and YouTube, as well as a selection of third party apps that support video out.
Connect your camera and a monitor/TV
And then there are the apps. The rich iPad apps library means you'll be able to find apps to cover anything you can think of - and quite a few for things you haven't thought of yet. The iOS limitation of only being able to display one app/window at a time can be worked around somewhat by using the free Dual Browser app. As the name implies, it lets you view two webpages side by side, but you're not limited to just plain web pages - you can take advantage of web-based apps for email, word processing (Google Docs) and YouTube to use this app for advanced notebook-style multi-tasking.