user23874: My question is: What is on an Arduino board besides the microcontroller? 

user7728: When I first built my first Arduino clone, I fount very useful the Fritzing examples (boards and schematics). http://fritzing.org/home/ 
Mind that in order to upload sketches, an FTDI module is very handy (unless you use ISP via another Arduino board).
In any case, I should recommend you to build an Arduino clone on a breadboard, before trying soldering. 
Good luck.
Additionally, you may use this picture (this is how  I create an Arduino on breadboard):

External power (battery) is connected to the screw pins (bottom left of the breadboard).

23874: <p>My question is: What is on an Arduino board besides the microcontroller? </p>
 7728: <p>When I first built my first Arduino clone, I fount very useful the Fritzing examples <em>(boards and schematics)</em>. <a href="http://fritzing.org/home/" rel="nofollow noreferrer">http://fritzing.org/home/</a> </p>

<p>Mind that in order to upload sketches, an FTDI module is very handy <em>(unless you use ISP via another Arduino board)</em>.</p>

<p>In any case, I should recommend you to build an Arduino clone on a breadboard, before trying soldering. </p>

<p>Good luck.</p>

<p>Additionally, you may use this picture <em>(this is how  I create an Arduino on breadboard)</em>:</p>

<p><a href="https://i.stack.imgur.com/6RV5c.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/6RV5c.jpg" alt="enter image description here"></a></p>

<p>External power <em>(battery)</em> is connected to the screw pins <em>(bottom left of the breadboard)</em>.</p>
