Summarize this article in one sentence.
You want to make sure you purchase a hard solder and not a soft solder. A soft solder will not work with silver jewelry, and may actually damage it further. You can purchase hard silver solder online, or from a local hardware store. You can choose to buy solder wire, or sheets. The sheets are generally cheaper, and will allow you to cut the size you need. Soft solder can be soldered with a soldering iron, which is electric. Hard solder must be soldered with a torch, with is powered by gas. Butane torches are useful for standard jewelry repair jobs like fixing jump rings and reattaching small chains. Always handle soldering torches carefully. Wear protective gloves and make sure you are in a room with good ventilation to avoid inhaling any fumes. Flux cleans the metal prior to soldering so that it can bond and melt properly. Use a liquid flux to coat the surface you're soldering before beginning. You can also purchase flux sprays made specifically for hard soldering, and for working with silver. Hard soldering might also require pickling after being soldered, in order to clean it. You can purchase separate pickling liquid, or you can even use a flux that is self-pickling. Brush flux onto the joint or surface you plan to solder before applying the solder. If you are soldering two pieces together, for example, place the solder wire against the spot you need to solder. Adjust the torch to its highest temperature setting, and heat the wire until it melts. Once it melts, it will join with the silver piece you're repairing or bonding with another piece. After soldering, you will want to rinse the newly repaired or joined piece in water, then pickle it to clean it if the flux you used wasn't self-pickling.

Summary:
Use a hard silver solder. Use a soldering torch. Use flux when soldering. Use the torch to solder the silver pieces.