First and most important step to succesful 3D printing is to understand how 3D printing works in general and how this applies to your 3D printer. Once you understand what your 3D printer actually does while printing and how external factors can influence printing you can troubleshoot your problems with ease.
There are multiple types of 3D printing techniques, but we are focusing on the most popular and afordable one: fused filament fabrication (FFF) or fused deposition modeling (FDM).
A 3D printer essentially works by extruding molten plastic through a tiny nozzle that it moves around precisely under computer control. It prints one layer, waits for it to dry, and then prints the next layer on top.
Full article: 3D printers
Sounds easy, right ? Except it’s not, as we don’t live in an ideal world. There are a lot of factors that influence 3D printing starting from the quality and precision of the 3D printer itself, type and brand of material you’re printing, bed surface, room temperature and humidity, slicer settings etc. But don’t worry, advances over the past years have improved material printability and also printer parts got cheaper and so did the printers themselves.
The 3 main components of a 3D printing environment are:
A good video overview of the whole process is 3D printing 101 - The FFF 3D Printing Process.
Next step: Overview of a 3D printer