Here are some general tips and tricks:
Pick your solder. Ordinary electrical rosin core solder is a mixture of tin and lead, called 60/40 because it's 60% tin. Silver bearing solder adds some silver to the mix. Radio Shack has 62/36/2 which is 2% silver. Rolls Royce solder is 5% silver. For practical purposes the 60/40 is thicker, easier to use and cheaper. Purists dig silver bearing solder. It's harder to work with because it's thinner, meaning you need to feed about four times the length to achieve the same solder mass at the application point. Try both and see. Run screaming from acid core solder which is used in plumbing to join pipes.
If you use an ordinary iron you'll need at least two hands, one to hold the iron and one to feed the solder. How to hold the parts? Locking pliers can help steady heavy cable to keep the exposed ends properly oriented. Clean needle nose pliers are useful for twisting and bending bare wire. Greasy fingers work too but it's your choice. Wrapping a rubber band around pliers' handles to hold them shut can fill in for locking pliers.
Try working atop a piece of corrugated cardboard like from a packing box. Although it is flammable, a lack of spare hands sometimes requires pressing the parts against something stiff. The air layer in the cardboard prevents heat from drawing away from the parts. If you char the cardboard just move over to a clean spot.
Plug the iron in and set it on its stand or otherwise in free air. Put a block over the handle to hold it down if you have to dangle the hot end over the edge of a bench. It takes a little while.
Start with clean parts or bare wire. If the parts allow, make a physical connection between them. For example, crimp the connector around the wire or thread a half loop of twisted wire thru the hole. Where no physical connection is possible get the wire to touch the part by setting up any combination of bricks, levers, blocks, wedges and pliers.
After the iron's been heating a while, it helps to tin its tip by melting some solder onto it. This gets the flux smoking and it's OK. Tap the tip lightly onto the board to remove big globs. Wipe charry bits off the tip with a damp paper towel.
The whole idea with soldering is to heat the junction of the part and the wire. When the junction is hot enough feed the solder into it without touching the solder to the iron. The solder runs towards the heat like a magnet. If you get the iron too close all the solder will run onto it instead of where you want it. Once you've got enough solder in the joint withdraw the unheated solder supply. Keep heating the part until the flux smokes off and the solder makes a nice smooth and shiny lump. Withdraw the iron. Keep the parts steady for a few seconds while the solder cools. Don't touch it to see how hot it is. Marvel at how much solder some heavy speaker cable can absorb.
If you're clever, hot flayed wire can be used to wick up excess solder from a sloppy job.
Above all, be patient and have fun. Relax. Buggering up the first one you do is part of the learning process.
