RE: having trouble soldering
First thing is that every surface has to be clean and shinny.
I'm going to assume your iron is one of the pencil type with the long, skinny tip.
Take a file and file either a round pencil-type point or a 4-sided wedge-type point. Make sure the tip is clean with no black pits in it. This can be done when the iron is cold.
Make sure your solder is either a 'rosin-core' or is 'solid-core' (nothing inside the solder).
If the solder is 'solid-core' you'll need a tube or tin of rosin. This is used to allow the solder to stick to the surface you are trying to solder. Without it, the solder will just roll off in little balls. It's a good thing to have a little rosin available anyway whether you are using 'rosin-core' solder or not. I always put just a tiny bit of rosin on all my solder work.
DO NOT, UNDER ANY CIRCUMSTANCE USE "ACID-CORE" SOLDER! This is the kind of solder plumbers use on water pipes. The acid in the "acid-core" solder will cause corrosion on electrical parts and will it will eventually stop working.
Plug the iron in and give it about 10 minutes to heat up. When you see the shiny tip begin to turn blue or black dunk the tip in the rosin quickly to put a light coat of rosin on it. Then immediately put some solder on the tip to "tin" it. The solder will flow around the tip and it will be a nice shiny silver color.
When you solder items make sure they are nice and clean, too. Some wire comes already tinned (silver colored) and some do not (copper colored). If the wire is copper colored make sure it's shiny like a new penny. If it's dull you may need to scrape the oxide off with a knife, sandpaper, or some other rough-surfaced item.
I cannot stress enough that the surfaces to be soldered and the tip of the iron has to be clean and shiny before you apply any heat or solder!
If you are soldering 2 or more wires together, you should twist the wires together before soldering rather than just laying them side by side, although you might not be able to do this in all cases. If you twist the wires together you don't need to tin them first, but if you lay them side by side you MUST tin them first.
Put your iron on the joint to be soldered and let it heat up for a few seconds. Then apply the solder to the JOINT, not to the iron. You want the joint to be hot enough to melt the solder to prevent what's call a "cold solder joint".
Apply just enough solder to fill any gaps in the wire and joint. Don't glob the solder onto the joint, it's not necessary.
Remove the solder from the joint and then remove the iron. Let the joint cool before you move it. If you've twisted the wires together that should be enough to keep them from moving for the few seconds it takes for the solder to cool, but if the wires are just laying side by side just the slightest movement could loosen the bond and could create a cold solder joint within the solder.
If you are soldering a wire to heavy tab-like material, like what's on a Deans connector, tin both the wire and the tab first.
Then lay the iron on the bottom and the wire on top of the tab. Let the iron heat the tab until it melts the solder and bonds the wire to the tab.
Make sure the tab gets hot enough to just melt the solder but not so hot it melts the plastic of the Deans connector. This might take a little experience before you are totally successful, but it can be done quite easily.
Post back if you're still having problems. Try to be as specific as you can with your questions because I think I've covered just about everything except for specialized soldering like on printed circuit boards and very tiny items.
Good luck.