Step 2: Getting ready
First things first, the tip of the soldering gets hot - up to 800 degrees Fahrenheit, so don't touch it. I know this seems obvious, but many people seem to burn themselves at some point while soldering.
If you're using a new soldering iron you will want to put a small amount of solder on the tip of the hot iron before you start working. This is called tinning the iron and you only have to do it with a new iron. Once you start using it will usually have some solder on it already and be ready to go.
Once the iron reaches temperature (some irons take minutes to do this and some irons take seconds), I like to clean the tip of my iron on a wet sponge. You can wet the sponge on your soldering base if you have one, or you can just use a damp sponge or steel wool. Gently touch the tip of the soldering iron to the sponge and clean off any old bits of solder that might be stuck to it. It will sizzle a bit; this is normal.
I asked Mitch, a soldering expert who works at the control tower by day and is numberandom by night, for some tips. Mitch showed me a good idea for how to hold solder wire: he cuts a piece of it off the roll, and then makes a coil at one end with a short lead at the other. This helps him hold it steady and apply just the right amount of solder. This is a way better idea than trying to hold the whole spool of solder or grab onto just one thin strand.
Next it's time to pay some attention to the material you're soldering. If you're soldering wire, you'll need to strip back about 1/2" of insulation to expose the bare wire. If your joints are going to be wire-to-wire or wire-to-lead, you can twist them together tightly before soldering. Electrical components placed on a circuit board don't need much prep work; just seat them where you want them and find a way to hold them in place with clips or by bending the leads outward slightly so they stay put when you turn the circuit board over.
Finally, place what you want to solder into the clips on the helping hand, or on a surface you don't mind getting a little burn mark on - scrap wood works well. Basically you just don't want the components moving around on you when you go to solder them. There are lots of ways to orient the wires/components so you don't have to hold them in place while you solder them. Find what works best for you.
Hopefully your soldering iron has reached temperature by now, because you're ready to solder!