Designing infographics is a large portion of what I do. Here's a rough breakdown of what I use.
- Probably 95% of the work on infographics I do is in Illustrator. You'll want to keep everything in vector format as much as possible because accurate scaling, aligning, grouping, tweaking and changing are so important. Illustrator has a few features that make it preferable to other vector programs:
- Its chart tools, which are rusty and frustrating but accurate and worth using (a few tips: remember to use s and r to scale and rotate, normal methods don't work, and when you need to break and ungroup the charts, always keep a grouped copy) and beat the workarounds needed in Corel Draw. I gather that Inkscape has some plugins and is improving in this regard while Adobe neglect their frankly antiquated graph tools, so this might change, but right now Illustrator is still best here. Don't be tempted to copy, ungroup and edit charts from Excel - it works, but somewhere along the line the vectors get distorted.
- Its features to apply effects to accurately drawn shapes in an adjustable way, like pattern brushes and transform effects. Other vector programs have features like these, but not to the same extent. Anything that makes elements re-usable, tweakable and reconfigurable helps.
I rarely use InDesign unless a graphic is to be part of a multi-page document. Two exceptions:
- Anything built around a table format (even then, it's a good idea to keep wholly graphical elements as illustrator files and place them as needed - particularly for anything adjustable based on data like sparklines - InDesign is fine for placing data but can't do anything with it)
- If it's text-heavy, with a heavily structured magazine-y layout (place in graphics from illustrator files as above)
Photoshop is occasionally very handy for the times when using raster graphics is unavoidable, and Fireworks can be handy for preparing complex things for web or for a suite of variants with the same basic structure. I use both quite rarely for infographics, although there are some people who design one-off simple infographics for web mainly using Photoshop or Fireworks.
People sometimes use more simple programs like omnigraffle for simple diagrams, and the idea of low-barrier-to-entry infographics creation tools sometimes gets floated around, but those I've seen have been either just a bunch of pre-made infographics in disguise (e.g. visual.ly create) or ludicrously shallow (e.g. easel.ly).
There are now a couple of low-barrier-to-entry tools that don't 100% suck and that add something worth mentioning to the standard infographic format (Vennage and infogr.am). They're early stages and a bit crude, and since they are essentially toy apps they're unlikely to ever be much use to designers except for in-house people avoiding mind-numbingly trival work ("Text and a couple of charts? That's really simple, you can actually do that yourself, here's how...") - but there's something worth noting about them: they export as HTML and SVG (infogr.am uses raphael, Venngage uses HTML, CSS and D3).
Why does this matter? Because if you design infographics for publishing on web pages, and if you just whack up a png or gif and say job done without using methods like this to output the text as actual, real, live, semantic text in the web page's markup, this will mean that cheesey automated toys like these sites are going to be producing output that has an advantage over your work... I always use raphael for things like this because it's the only thing that works in old IE and iOS.