+1 to The Maker's Muse that was mentioned, but also I think it's best to learn by doing, so I encourage you to grab some of the simpler STL files on https://thi

+1 to The Maker's Muse that was mentioned, but also I think it's best to learn by doing, so I encourage you to grab some of the simpler STL files on https://thingiverse.com https://thingiverse.com and try printing them. It soon becomes clear what how long different types of print take, what kind of designs are easy or difficult, and reading the comments from others throws up further insights, such as the effect of different materials, etc.