Almost anything can be learned by Googling it -- the same is true for 3D Printing. 

An excellent article from GrabCAD, this article goes in-depth for design principles in FDM, and is well worth the read.

From the article: 

This tutorial is designed to give you a foundation of what to consider when designing and printing a part for Fused Deposition Modeling (FDM).
FDM is an additive manufacturing technology that extrudes thin layers of thermoplastic layer by layer until a part is completed. FDM produces robust production parts in engineer-grade thermoplastic, with the added benefits of speed and design freedom possible with 3D printing. The cutting-edge technology is utilized across industries like aerospace, energy and transportation for production components.


Enjoy! Link below: