Sometimes the data comes first. If I run across a potential data set, I'll save it even if I don't have an immediate need for it. For example, I don't live in New York, but I still grabbed the NYC PLUTO data
last year just to see what I could do with it (nothing worth publishing yet). A while back, I stumbled on some 60,000 reported UFO sightings that I've been trying to make something interesting out of. So in this regard I'm always on the lookout for new data sources that might be useful one day. Mapping/GIS/dataviz forums, plus Twitter for announcements, are probably where I stumble on data most often.
When I need to find a particular data set, it's often as straightforward as a search for the topic with the word "shapefile" or "gis" attached. There's *so much* data just sitting on servers that if you can imagine it, it's probably out there somewhere (often for free). Sometimes though, finding data requires a deeper search. A lot of government-provided data sits inside un-indexed data portals or clearinghouses. Depending on the quality of the portal, these can be tedious to sort through.
Occasionally, I must create my own data using old-school GIS techniques like digitizing from maps or photos or geocoding addresses. And of course, as a last resort, some commercial vendors have data for purchase.
Do work with maps in your day job?
Not maps per se. My day job involves data wrangling and product development around the oil and gas industry. I am constantly working with geographic data–evaluating its quality, performing analysis, making corrections and so on–but very little of what I do on a daily basis involves any cartography beyond basic visual inspections.
So I do maps on my own to keep my skills sharp, try new tools and techniques, and settle my own curiosities.
How did you come to online mapmaking?
I'm not sure if what I do is proper online mapping. Sure I use the web as my primary medium (it's a great way to find an audience fast), but I've never published a truly interactive "online" map with embedded data behind it. Instead, I stick to static maps for a few reasons:
Simplicity and ease-of-use
: Interactive maps are great, but I want the maps I make to be straightforward to read and understand. I don't want viewers to have to figure out how to use the map; they should just be able to look at it and figure out what's going on.
: Typical web maps are limited to the Web Mercator projection. I don't have any objection to Mercator in principle (in fact it's brilliant for what it does), but I can't in good conscience use it for maps at a continental or global scale. Sticking to static maps allows me to choose more appropriate projections for the data and region I'm depicting.
: I want everyone who visits my maps to be presented with the same information. I don't want some algorithm deciding that one visitor is shown a particular view while another visitor gets a different one.
That said, to your question. I always enjoyed geography as a concept growing up. I was always studying maps and globes. In elementary school, I remember plotting all my friends' addresses on a paper map of the city. And when the family would go on road trips, my head was always buried in the AAA TripTik.
But it wasn't until well into my professional career that I discovered a real passion for maps and geography. I got started in the field in earnest about 5 years ago after spending the previous 10 working various roles in the publishing industry (newspapers, magazines, advertising). When wearing my graphic designer hat, I was occasionally tasked with map assignments. Back then, I didn't know anything about GIS, so all the maps did were hand-drawn. For one assignment, I made, by hand, a 3D map of downtown Atlanta using Sketchup before I had ever even heard of a shapefile.
Eventually, I tired of the publishing biz. When I went searching for what to do next, I rediscovered my enthusiasm for geography. I went back to school, got a new degree and started playing with tools and data. I feel incredibly fortunate that my geospatial education coincided with the explosion of the "neo-geography revolution" of the past half decade or so. With the fundamentals of a "classic" geography education and access to contemporary tools and sources, I'm having a great time making maps and taking names.