For the study of techniques, materials, devices, etc., regarding 3D printing, there’s no single best source. That is, unless one’s talking about “the Internet.” The search bar is truly your friend.
That said, what follows are some tips picked up from personal experience. The intent is to help you achieve some early success, maintain your sanity when things go wrong—and they will—and avoid some troubles that are easily preventable.
Thinking of buying?
If you are thinking of buying your own 3D-printer, before buying, do some research. Make: magazine has a yearly issue comparing various machines offered for sale. Think about your needs and wants from the machine—also think about what you’re willing to spend. Accuracy, print-speed, working envelope, vendor lock-in, open-source vs. closed source and user interface are all things to think about.
In starting with the 3D printer, the first—and IMHO, the best—advice you’ve probably seen given is “spend the time to properly calibrate your printer.” This really can’t be over-stated. Time spent doing this will, without any doubt, save you tens of times the effort and aggravation of dealing with a “near-enough” machine.
Level it (and keep it leveled)
A frequent source of failed prints is a mis-leveled print-bed. On some printers this is more of a problem than others, because of the difficulty of getting to the leveling mechanism, or the tendency of the machine to easily go out-of-level.
Secure all “loose parts”
Anything that’s floppy—cables, for example—that can possibly interfere with the mechanism at any point in its travel is a potential source of continuing troubles.
Settle on a solid filament supplier
Filament suppliers are getting better, but there are still some that offer more consistent product than others. Where possible, do some research. Look at the reviews on Internet buying sites—eBay, Amazon, AliExpress. Listen to people you know who are into 3D printing.
You may decide on a particular color scheme. Be aware that colors from vendor to vendor vary a lot. One day there may be an RGB (red-green-blue), CYMK (cyan-yellow-magenta-key) indicator or Pantone system to tell you of its color against a standard color-set. Unfortunately, that day is not today. For now, it’s probably best to find a reliable supplier and use the color(s) from that vendor you’ve decided on.
Depending on how your filament is dispensed to your printer, you may care about the spool dimensions. If too narrow, your spool may be pulled off. If too wide, it may not fit. If it’s an “air core,” you may spend time (more than you want) just watching that it’s feeding properly (and un-ravelling the mess when it doesn’t).
Settle on a filament type for the majority of your work
This isn’t to say that you’ll be limited to just one material. New materials seem to be coming out every few weeks. And for best results in specific jobs, some specialty filaments will have the most suitable qualities. PLA and ABS are—at this time, 2017—the most widely used and most available plastics for 3D-printing. I prefer PLA because all my printing is done in a room without good ventilation. PLA doesn’t have that “plastic odor” of something burning, is recyclable and non-toxic—as it’s biodegradable, it’s even used in implants.
Filament is hydroscopic—water-absorbent—to various degrees
If you live in a damp climate, or if your filament won’t be quickly used up, it pays to keep your filament dry. I use cheap styrofoam coolers with a small layer of kitty litter at the bottom to store my unused, but open-to-the-air filament.
Find the temperature your 3D-printer prints best at
As your “ugly blobs” turn into recognizable objects, you’ll likely notice that some temperatures work better than others. It can take some trial and error to find the best combination of hot-end and heated bed temperature.
As a starting point though, I’ll tell you that my printer, using PLA, works best at 190-200 deg. C for the extruder, and 55-60 deg. C for the print bed.
That said, the thermistors that sense the temperature on your machine are not identical to all others used. Thermistors may be anywhere within a range. (Check the specification if this is important to you). Also, the placement and degree of contact to the heated bed will cause some variation from one 3D printer to another—even those of the same make and model.
Typically, among the first parts printed are calibration parts—parts used to test how accurate and precise a printer and its setup are. Print several of these at different temperature settings and, while doing it, note which are doing a better job: less “stringiness” or “drooling”, fewer “pimples” stuck to the outside of the part, less “droop” over empty spaces, and better sticking to the bed. (Regarding “sticking to the bed”, my experience is that the biggest problem with prints not sticking is bed-leveling. The second biggest problem I’ve found is that when corners “curl” upward, the bed temperature is set too high. I read somewhere that the bed temp shouldn’t be set higher than 65 deg. C. I concur. This fits my experience).
Develop different slicing models for different parts
A large, squat part needs a different slicing model than one with fine features, or one with limited bed contact, or one that needs to be as stiff as possible, or as light as possible.
Slicers allow you to create different models for each of these situations, and more. The large squat part will print much more quickly if its percentage of “fill” is reduced. The part with limited bed contact will stick to the bed more securely with a wider “brim”—plastic placed around the periphery of the part—than a narrow brim or no brim. A part needing to be stiff may benefit from a solid layer every few layers or from a honeycomb infill pattern. Fine-featured parts may benefit from being printed more slowly than others, etc.
As you examine the part about to be printed, think about what’s “special” about that part. How will it be used? What special treatments would it benefit from? And then use, or create, the slicing model you think is needed.