Bleach
The cheapest and most readily available sanitizing solution is made by adding 1 tablespoon of bleach to 1 gallon of water (4 ml per liter). Let the items soak for 20 minutes, and then drain. Rinsing is supposedly not necessary at this concentration, but many brewers, myself included, rinse with some boiled water anyway to be sure of no off-flavors from the chlorine.
Star San
Star San is an acidic sanitizer from the makers of PBW and was developed especially for sanitizing brewing equipment. It requires only 30 seconds of contact time and does not require rinsing. Unlike other no-rinse sanitizers, Star San will not contribute off-flavors at higher than recommended concentrations. The recommended usage is one fluid ounce per 5 gallons of water. The solution can be put in a spray bottle and used as a spray-on sanitizer for glassware or other items that are needed in a hurry. The foam is just as effective as immersion in the solution. Also, the surfactant used in Star San will not affect the head retention of beer like those used in detergents.
Star San is my preferred sanitizer for all usages except those that I can conveniently do in the dishwasher. A solution of Star San has a long usage life and an open bucket of it will remain active for several days. Keeping a solution of Star San in a closed container will increase its shelf life. The viability of the solution can be judged by its clarity; it turns cloudy as the viability diminishes.
One last note on this product: Because it is listed as a sanitizer and bactricide by the FDA and EPA, the container must list disposal warnings that are suitable for pesticides. Do not be alarmed, it is less hazardous to your skin than bleach.
Iodophor
Iodophor is a solution of iodine complexed with a polymer carrier that is very convenient to use. One tablespoon in 5 gallons of water (15ml in 19 l) is all that is needed to sanitize equipment with a two minute soak time. This produces a concentration of 12.5 ppm of titratable iodine. Soaking equipment longer, for 10 minutes, at the same concentration will disinfect surfaces to hospital standards. At 12.5 ppm the solution has a faint brown color that you can use to monitor the solution's viability. If the solution loses its color, it no longer contains enough free iodine to work. There is no advantage to using more than the specified amount of iodophor. In addition to wasting the product, you risk exposing yourself and your beer to excessive amounts of iodine.
Iodophor will stain plastic with long exposures, but that is only a cosmetic problem. The 12.5 ppm concentration does not need to be rinsed, but the item should be allowed to drain before use. Even though the recommended concentration is well below the taste threshold, I rinse everything with a little bit of cooled boiled water to avoid any chance of off-flavors, but that's me.
Heat
Heat is one of the few means by which the homebrewer can actually sterilize an item. Why would you need to sterilize an item? Homebrewers that grow and maintain their own yeast cultures want to sterilize their growth media to assure against contamination. When a microorganism is heated at a high enough temperature for a long enough time it is killed. Both dry heat (oven) and steam (autoclave, pressure cooker or dishwasher) can be used for sanitizing."
