A lot of people are now using laptops as their main computers. They are handy, portable, and allow you do work from almost anywhere. The trouble is that if you are planning on using a laptop as your main computer, you'll probably need a bit of extra gear, to make using it for long periods of time livable. Don't get us wrong, we love our laptops, but working for hours on a stretch on one can get painful.
When working from home, it's best to get an external keyboard and a mouse. If you're on a budget and can't afford to get an external monitor, then a nice stand would also be needed. Check out this stand that can be made with some IKEA bits. With these three devices, you'll extend the use of your laptop by quite a bit. The new Apple Bluetooth keyboard looks clean, but I like having a numeric pad on my keyboard, so I'd go for something from Logitech, preferably with some LED lighting for nighttime use.
It's more convenient to get a good travel mouse than a dedicated mouse to use at home. Sure, you'll be using more batteries, but it makes no sense to have two mice if your only computer is a laptop. The Logitech Anywhere MX Mouse is a good option. It works on glass, so that's pretty convenient.
If you can get yourself an external monitor for you laptop, then you should. It transforms your laptop into desktop, from many aspects. You'll also extend the life of your laptop screen by doing so at home. You can check out this guide to the different things you'll need to know about monitors. To get a really good monitor, expect to spend between $500 and $1,000. Apple products will cost more than other brands.
Lastly, having an external hard drive will allow you to save and dump some files off from your laptop. Depending on your media use, you can easily get 500GB-2TB without any problems. When you come home, and when you need to dump data or access some files, you just plug in this external hard drive. It's preferable to get one that has an integrated fan, as the ones without can easily overheat.