1. make sure you use thin rosen core solder;
2. use soldering paste;
3. use a soldering iron or gun with ample wattage such as the small black "Weller" gun with a clean tip.
(It should be silver without any crud.)
4. for circuit board work you will need a low wattage soldering pencil/iron. If you don't understand this .. don't attempt working on a circuit board.
5. wear jeans or cover your legs, solder can drip or shoot, it will burn exposed skin.
4. Practice, practice, practice ... once you get the hang of soldering it becomes a very easy task.
Good soldering!