I have taken this information from the website listed below. I have added my own information to it based on experience.
Immature chile peppers are green chiles, and, when left on the plant, they ripen and become red chiles. This is good to know because if you want to dry your own red peppers you can and you can make your own red chile recipes with it.
The spicy, hot taste of a chile depends on how much capsaicin is produced. The variety of chile plant influences this, but so does air temperature and Gardening practices like fertilizing and watering. Capsaicin is concentrated in the yellow ridges along the inner walls of a chile pepper. The seeds really aren't hot until capsaicin pustules burst onto them. Hot, dry weather promotes production of capsaicin.
So based on this information a friend of my husband told him if he wanted hot chile not to water them so much. He tried it and our chile was so hot no one could eat it. Not even my mother who loved her chile hot.
Choose chiles on the basis of pungency. A very mild chile variety is NuMex. NuMex Big Jim or 6-4 are chile varieties with a medium bite. For hot chiles, consider Sandia or Espanola Improved. For the brave, some very hot varieties are Jalapeno and Cayenne. I like Anaheim or Big Jim because they are both good sized and meaty.
Plant chile transplants about the last day of May, or when night temperatures consistently remain above 50 degrees Fahrenheit. It's best not to plant chile peppers where close plant relatives were grown in the last year. These include tomatoes, eggplant, potatoes and tomatillos. The same diseases that affect these plants will affect chile plants and may carry over from year to year.
Space transplants about 24 inches apart and fertilize them with a weak water-soluble fertilizer. Fertilize the chiles again in four weeks. Water chiles regularly through the growing season. Excessive water can cause root disease, especially in heavy clay soils.
Harvest green chiles when the peppers are firm and a glossy green, usually in August. Green peppers left on the plants will turn entirely red and be ready for harvest by late September.
When your green chiles are ready to harvest you can roast them outdoors in the barbeque. If you roast them in the barbeque it is easier to turn them and you won't have to worry about cleaning the oven. You want the skins to look toasty brown and then simply put them into a bowl with a clean wet towel on top. Let them steam for awhile this way and when they are cool enough to handle you put olive oil on your hands and skin them then put into freezer bags or use for your recipe.
If you want them red you can string them up with dental floss and let them dry, as they do they will redden, or you can harvest them red then string them up to dry.
A good suggestion for chile is to go to the store and look at the chiles and their names and write it down. You might even buy one of each and take them home to try then, based on your personal preference, choose your chile seeds. You could even remove the seeds and let them dry and try planting them. I have a friend who plants her garden this way. She buys organic vegetables and harvests the seeds right out of the vegetable for her garden. She buys no seed in packets.
My personal favorites are poblanos often used for chile rellenos, Big Jim used for pork green chile, and jalpeños to add a little zip to chile or salsa.
While you are growing your chiles you might as well plant tomatoes and cilantro and have a salsa garden if you are a salsa lover. If you want to purchase the chiles you haven't grown there are vendors every year that sell them fresh roasted. In Longmont you can buy them on Main Street, in Denver on S. Federal Blvd, and everywhere else the farmers markets are now carrying them.
Remember, there is nothing in the whole world like a home made salsa or pico de gallo made with fresh vegies and herbs.
