A home office is a place of refuge for doing important work. Setting one up in your home should be taking with proper preparation. Converting a spare bedroom or basement are is typical in most homes.
First off, how much desk space do you need? IBM did a study with their developers and found that they needed about 30 square feet of desk space. This is about the size of a couple of desks. Which makes a certain amount of sense one deck for a computer and another for writing and organizing. If you are looking to maximize your space adding shelving above the desk is a good idea.

Second, how will you organize it? This is obvious but most people forget this step in the hustle and bustle of putting it all together. Put your most used items at the places they are most used, put the things used often next to the places they are used and things rarely used can be across the room.
For example put the printer near the computer, the paper next to the printer and the ink cartridges can be in the cabinet above the printer.

Third, get a good chair. If you have the potential of banging away at the computer for a few hours a good chair will really help out. It will save your back, hips and shoulders from extra pain.

Finally, set up a household management station. This is the place for paying bills that has all the things you need: stamps, envelopes, pens, checkbook and so on.
Just remember to take them to the mailbox.