Serving as both a convenient way to control light and a lovely form of window treatment, roller shades are an excellent addition to many types of rooms. There will be, however, several practical and aesthetic concerns you'll want to think about before buying them.
Roller shades are a subset of blinds, and they're designed, as the name suggests, to roll down and up in order to deploy and retract them. This allows them to be used very quickly, a convenient feature for when you need to block the sun or create some privacy. Fascia is sometimes used to cover the rollers, too.
One of the big things that distinguishes different types of roller shades from each other is how they're operated. The cheapest models use a spring-loaded roller that can be manually operated simply by pulling on it to deploy and tugging quickly to trigger the spring for retraction. There also are models that use string to pull the roller, and you can even find more advanced ones that use mechanically controlled rollers. Thanks to improvements in home automation technologies, you can even get ones that can be configured to deploy or retract on their own at specific times of the day.
The choice of available materials for roller shades is quite diverse, ranging from vinyl slats to full sheets of fabric. Vinyl models will be lower maintenance, and they're less costly to replace when they break, but they also tend to lack visual appeal. Fabric can look amazing, but it also can age poorly, especially due to fading from UV exposure. You can also look at options like wood and bamboo.
A great deal of decision-making when it comes to buying roller shades boils down to the size of the shades you'll be installing. There is a point at which hand-operated models cease to be practical due to the weight of shades. In these situations, you'll have to either look into a motorized system or use two or more shades to produce the desired coverage.
If you're bringing in a contractor to handle the job of installation, you'll want to know they're qualified. The Window Coverings Association of America is the most widely recognized professional organization in the business. Licensing requirements from state to state are fairly sparse, although a few, such as California, do require a license for putting in window coverings.