Tools are important, after all. Not everyone has the luxury of an actual office, but do what you can to create both a time and space for writing. Whatever works for you and your budget. About 10 years ago, I splurged on a really good chair. It remains comfy and in good shape, and I still don't need a new one.
I like to plot and "What if" in a notebook. It's a stress free place where the quality of the idea and written word doesn't matter, it's not even the point. The notebook is for brainstorming, it prepares me for sitting at the computer at which point I often end up doing something completely different. I do most of my brainstorming just before bedtime, but I carry a notebook (not the same notebook, I have one for home and one for travel). I make sure several of the Pen of Choice are with me: in the car, with the laptop, pretty much wherever I go. Never know when you'll have some free time. Be prepared.
I had to find a new pen of choice since the Sanford uni-ball, micro 0.2mm. recently began breaking at the point, often within days of use. Well, rats. So, the new Pen of Choice is the Pilot Precise V5 rolling point, Extra Fine. Black for the notebook, Red for editing paper copy. I also have a glass pen which is sometimes fun to use, as long as the cat doesn't think it would be fun to knock over the bottle of ink.
I recently replaced my "office" computer with an iMac. The laptop is still a Dell. If you're buying a PC, double whatever RAM the system comes with. If you want your computer to last 5-7 years you need RAM before hard-disk size. This strategy has stood me in good stead over the years. Lack of RAM will cripple you even more than lack of processor speed.
The refurbished laptop died so I replaced it with a Dell Latitude with Win XP. I love the laptop but still have, sad to say, nothing but very unkind thoughts about Dell Customer Service. They ought to have some. Immediately maxed out the RAM when I bought it.
An HP LaserJet 3500dn with a paper tray that holds a ream. Prints 25 ppm. Never a moment's trouble. Works like a charm. Thank you HP. When I started out years ago, I had a daisy-wheel printer and an Apple IIc. Printing 400-500 pages took me 9 hours, no fooling. My printer does duplex. Heaven.
I use WordPefect X3 for writing. It's a superior product. It just is. I feel sorry for all those poor souls using Word, I really do. I run it in Parallels on the iMac.