For that other part of my life, the writing fiction part, there's been a lot of people who have been open with various figures on their earnings, advances, etc. Which I have to say is totally fabulous and for any aspiring writer one should find those to have a big dose of reality. And I thank all those who have done that sharing (Tobias Buckell, Jim Hines, and John Scalzi leap immediately to mind)
For the day thing, fortunately we have a few organizations who started publishing salary and compensation data about a decade ago. This was a way for us to judge just how well we were being compensated (the design field had been notorious for under payment and wage theft, although I think we've hammered through most of that now). So here is one of those for the current year (please note, they're lumping a lot of regions and job responsibilities together for these numbers - one of the other reports typically runs about 30-40 pages- but I am slightly sad to see I'm on the lower end of my range - possible combination of smaller market, depressed conditions, and working "in house").
Find design jobs and careers at HOW Design.
In case you're wondering about your own field, Indeed.com has a nice little salary tool you can use to enter the position title and your location to see how you compare (note, I don't know what data Indeed is using for their tool, but that's just because I haven't taken the time to research it).