Yes your home is your haven but that does not mean you don't need an office. Even if it only for personal details, files, bills and so on, it is always necessary to have somewhere to store this.
I have been to some houses where they have papers thrown all over the place, files out and it looks such a mess. To keep a good order can be as simple as putting up a few shelves. If you want something more substantial than shelves then you should look at getting yourself a whole desk unit.
Find an area in your home, whether it is a niche close to the living room or a small room that is not used or even a corridor space and decide if that is suitable to make into a mini office. If it is then you can start measuring up and deciding what you want to put there. You can either go with a ready made desk with drawers and shelves or try one of the DIY places to put together a whole system. Whatever you do choose to go with make sure it is practical and has enough room for you to add things at a later date.
For example you may need a computer there so make sure your desk is large enough to house a computer and a printer still leaving you space to write and do work. I stupidly bought a computer that I thought would fit into a niche on my desk with the shelves above it and because I did not measure properly, my computer does not fit under my shelf and I do not have any writing space since I also have a large fax/printer next to the computer.
Another thing to think about is to make sure you have enough leg room. If you are planning on working in your office at any time you want to be able to sit comfortably and not be squashed. Choose a material for the unit that is hard wearing and will not chip - wood is probably best if you can afford it and make sure the shelves are thick so that they don't bow when heavy books and files are put on them.
Having a convenient and easy office space is important for an efficient running of the household and should not be belittled. So think very carefully when choosing where and how you make an office.