Hey guys, this has been a while, but i just got the RasPi
i also bought a pair of motor, some wires, and an motor control chip (IC L293D). Woo! Im exicited, the possibilities that you could think of to do with this tiny machine... but I think i will to start with something simple first...plus...
i never used linux before and just started to learn how to, dont worry thou, im going at a slow but steady pace here.
To add my own bit: To just use the Pi, you don't need to go into the GPIO stuff. Power in through a (USB ?mini?1-ended) plug from a standard wall-socket-to-USB arrangement, HDMI video cable out into a suitably-equipped monitor2 and your choice of USB keyboard and mouse3 and it works perfectly fine just off of a suitably pre-initialised SD card.
Add an ethernet connection (network cable, RJ45) to your home network5 and you can even ditch the cable to the monitor and whatever you did for keyboard/mouse and run it through a VNC window on your standard computer (once you have it set up - guides on how to do this available through your standard search engine) leaving just power in, whatever network connectivity it needs and the rest only as you need to for specific other interfaces.
Only when you want to do more than play with the "computer" aspects of the Pi (play the cut-down-Minecraft, mess about with the programming tools, just use its browser to browse the internet, experiment with shell-scripting to capture stills from USB cameras you have plugged into it, etc) do you need to worry about the GPIO and breakout boards that give you the ability to control robotics (of a kind that isn't USB plug'n'play already) and the rest.
And, to echo the last poster, if you're determined to go into electronics stuff (rather than PnPish things that may be an installation/configuration challenge, but not a "which pin do I connect to which transister or relay leg?" one) then get an Arduino (no fancy video output, you typically poke and prod it from your current computer) and a breadboard or other similar development kit to plug components into and wires into/out of. Not so "instantly use", but mid-way between Pi and a PIC controller board and on the way to the "create your own custom circuit board controller" territory.
You can later combine both Pi and Arduino into one battery-powered whole. Let the Arduino do a lot of the "electronicky" stuff (you can attach more separate servos to an Arduino, even before adding a special polyservo break-out board to it, than your Pi can service on its own) and the "lower level" coding, but with the Pi running as "higher brain functions", possibly with a touch-sensitive LED display 'hat' to it for you to handily interface with. But that's not where you'd start, or necessarily where you'd even finish or be passing through on the way to somewhere else even more technical...
1 I can never remember between Mini and Micro and the like, but it seems like the current standard for smartphone chargers/etc...
2 Depending on your model of Pi, you may be able to get 'Composite video' out of it (phono-style connector) and plug that directly into a suitable monitor/TV input, but it's easier just to go HDMI if you can...
3 To cut down on wires, and use only 1/4 of the USBs4, I have a Keyboard+Mouse pair that wirelessly connect to a USB "how the heck does this essentially flush plug contain a receiver?" dongle.
4 But I don't usually use the other three, and you can always add (ideally powered) USB hubs to the Pi to give it more USB devices to plug in...
5 You can also get Wifi USB dongles, and the newer Pi W has inbuilt wireless capabilities, though I'm not so sure about its other side-ports, such as I've been assuming you have on the 1A,1B and 2 version Pis.
Personally, I would recommend getting started on an arduino. They aren't as versatile as the PI, but they're simpler and easier to get into. I would recommend the UNO Elego, my version came with a starter kit filled with all sorts of parts and wires as well as an instruction manual that explained how to use each part as well as the programming language. It's honestly not that hard if you read the instructions and know some programming basics.
Funny really, i just recently knew what arduino is while i was browsing some chip and sensor for the Pi. Thou i never thought that the 2 could be combined, ill try to do that when my pile'o tresure is refilled.
A simple and easy project to just get started with how the Pi works would be making yourself an OSMC (open source media centre) system, or something like Retropie chock full of emulators. Neither require insane amounts of technical prowess, have some level of configuration required, and produce a pretty cool little talking point as the end product of the project. Once you make those, you could do something more complex by writing a program in Python. There's a video of a bloke who automated most of his home by singing to it with an ocarina.
Im getting onto that, got a 32gb sdcard for me to fill RetroPie, at first i thought those NES case was a joke/bells and whistle for the pi, i was suprised when i discover RetroPie, i totally dig retro games, heck, i had emulators on my phone and computer
Depending on the stack that you use to enable access to the gpios, accessing the pins states (both read and write) can be as easy as a simple filesystem read, because the states are represented on the /sys/gpio device block.
This means that you can easily monitor and control the pins to do a wide assortment of simple tasks, even just from a shell script.
I was also reading on this and wiring tutorials, but i realize that many guides uses the 1st gen of pi which has less pins than the RasPi3B (the one i bought). I have yet to discover whether every pin is consistent or i can change the function through editing the program, guess i need to experiment on these. I was very cautious regarding wiring the Pi. From what ive been loking into, the Pi is susceptible to current overloading and cpu overheating.
Again, thanks for the help everyone, always wanted to make a robot since i was a kid, back then i tried with lego nxt, but my dad found it to be somewhat unconvincing, then i tried FischerTechnik, was pretty good, but my mentor was...incapable (thats kinda mean to say, but i never learned much from him anyway...), i dropped robotics for a good few years, then kinda got back inspired after seeing what people do with RasPi. Maybe one day, when i made a sentient coffee machine, ill put you guys on the credits