That's bell pepper, for those in the US. They come in many different colors, but the "traffic light" colors are the most popular. The red and yellow varieties are sweet, and the green a little more bitter. (I prefer the green) For the health conscious among us, they are high in vitamin c and the red variety is high in beta carotene (which the body turns into vitamin A.) and they can improve your metabolism, lower your blood pressure and lower cholesterol.
How to select and store capsicum
They should be brightly colored, have a shiny skin, be free from blemishes, be heavy and firm and have a stem that is intact and green.
Store in a vegetable crisper. All fridges have them these days, don't they?
How to prepare capsicum
Chop off the top and bottom, rip out the membrane and seeds. Slice down to open, remove any remaining membrane. There's nothing that can be made with the membrane and seeds that I know of, but if you want to grow the seeds, only use the ones from red capsicum, as the yellow and green varieties are not ripe and will not germinate. Scrape the seeds off the membrane and let them dry for a few days, stirring them a few times to make sure that they dry evenly.
To slice, place open side down and slice into strips.
To chop, place strips on their sides and line them up, cut across. (The skin is far easier to chop through this way. Put the skin side down and you'll be there for hours.)
Recipes:
Nachos