I have worked from home part-time and full-time for nearly 5 years now. My home office has varied from a sole desk in a teeny tiny New York City apartment to a large room with tons of natural light in my current home in Durango, Colorado. Over the years, I've figured out what has worked best for my workspace and thought I'd share a few essentials.
First up, a high quality desk chair. I usually work from a modified standing desk (creating using an Ikea hack that my husband discovered), but when I need to sit (and I do a lot of sitting with my embroidery) I need a comfortable and supportive chair. The Aeron by Herman Miller is hands down my favorite task chair. It's a pricey investment, but very well made and with great support. I got mine off Craigslist for a steal.
Having a good lamp is also key. As I mentioned, during the day, I get an insane amount of wonderful natural light in my office, but come sundown, it gets pretty dark. I use this lamp from Lavish Home primarily for embroidery work, but it makes a great task lamp as well.
With lots of paper goods comes lots of inventory: sleeved cards, additional inventory, envelopes, mailers....it's never ending. These metal shelving units have been a lifesaver. I also have a number of wooden wine crates that are so durable and make great storage bins.
I mentioned that I use a standing desk. To achieve the best height for my laptop, I use this awesome stand found on Amazon.