I have found a good
pictorial guide for you.
Basically it is how I do it.
The pieces to be soldered must be clean. I like a hot iron, I use a 60 watt Weller.
I don't like lead free solder at all. You can still get leaded solder. Use the resin core variety. You should not use any added flux, other than what is in the resin core of the solder for electrical work, or you will get wire corrosion.
Now heat the first part to be soldered with a little solder on the tip of the iron. Then bring the solder to the part. It should be hot enough that it melts the solder right away and the solder should instantly flow over the part.
Repeat this with the other part to be soldered.
Now bring the parts together and apply the iron until the solder flows over both parts.
Remove the iron and hold still until the solder solidifies.
The solder union should be smooth and shiny.