Resources
This site's a bit ancient at this point, but might still help you find some resources I found useful when I was strongly into 3D printing, 2011 through 2018. I still use it, but am less involved in follow new technologies, etc.
Boston area people: also see the Boston-specific page for meetups, etc.
This page is my own take on worthwhile 3D print related resources. Mostly it's a collection of links, to the left. These are my personal opinions; I'm open to suggestions, email me. Quick link to this page is bit.ly/info3dp.
My advice: read 3DPI's guide for an overview or 3Der's basics page if you want to dig into things. Get the Make Magazine guide or view their buyer's guide online if you plan to buy a 3D printer - best $10 you'll ever spend.
For modelers, I don't include SketchUp, a lovely modeler but not so great for 3D solid modeling, or so I've heard from someone who works at a 3D print service bureau. Similarly, I don't list Blender, which can be used for modeling but is a surface modeler, so you have to make sure your model is watertight. It's possible, but you need to be careful.
Model creation tips: my mantra is "smaller is cuter is cheaper". For display, smaller, detailed models are often more impressive to people than larger ones, plus they're less expensive to make and print faster.
Me, my interest in 3D printing comes mostly from a hobby project, Mineways, for creating 3D print files from models made in Minecraft. I usually use the service bureaus Shapeways and Sculpteo to print my exports, because I print in their full-color sandstone/plaster material. In my experience, Sculpteo costs about 50% more and delivers considerably faster (even with them being in France).