You'll spend a lot of time at your home office desk. The chair you sit on will need to be comfortable and support you correctly. Other items of furniture will determine how efficiently you are able to work.
If you want your home office desk to have a more traditional look, then a pedestal desk is always a good option. You can often buy used ones, and you'll often find good antique ones also.
You'll find the height some computer desks (24"-27") are a little less than a standard desk (29"). This is because using a keyboard is best done at a slightly lower height, whereas normal writing is more comfortable a couple of inches higher.
When computer desks are the same height as normal desks they often have a pull-out platform for the keyboard. This serves two purposes. It allows the keyboard to be stored away when it's not needed, but also lowers it to a more convenient height for typing.
If you don't want to spend very much on a desk, you can make a very practical one by using two filing cabinets of a suitable height. Lay a strong piece of wood across the top to act as your desktop. Off cuts from per-formed kitchen work surfaces are ideal.
When commercial companies are renovating their offices, they often get rid of their old desks. There's usually nothing wrong with them, and if you can get one they are perfect for use as a home office desk.
Your home office chair
Most of your time will be spent sitting at your home office desk. It is very important to get the right sort of chair. In fact, even if you are using existing furniture - a chair, desk, shelves, etc. - do make sure your chair is suitable. If it isn't, get rid of it. If you're working to a restricted budget, spend all of it on a good chair.
Your office chair should be comfortable, easy to move around, and most importantly, provide good support. This is why swivel chairs on castors are often used. Ideally it will have a back which supports you as you move forwards and backwards.
It is essential to get a chair which you can raise and lower. This is because when you use a keyboard your lower arms and wrists should be parallel to the desktop. You'll need to adjust the chair height to get the correct position.
Arms are not necessary on the chair, and can actually be a problem. When you're using a keyboard they can get in the way, or stop you reaching down to open a drawer.
If you want some more information on furniture, then go to the home office furniture page.
If you have back trouble, you may want to try a 'Norwegian Balans' chair. With this chair you sit on a seat which tilts you forward slightly, and you rest your knees on a cushioned support. The chair works by easing pressure on your back, even though there is no actual back support. It keeps your spine straight and free from stress.