I'm going to let you in on a little secret: guitar string brands don't matter as much as string materials, construction, and size.
I know, "but the guy at Guitar Center said..."
What Are They Made Of?
It depends on what guitar you have, and what string you're talking about. For example, acoustic strings are different than electric strings. E, A, and D strings are going to be different than the G, B, and E strings on an electric. On an acoustic, the B and high E strings are different than the rest.
There are wound strings and plain strings on a guitar. On an acoustic, the G is wound. On an electric, the G is plain (not wound). The E, A, and D strings are always wound. A wound string consists of a steel core with another smaller steel wire wrapped around it. The outer steel wire is usually plated with nickel on an electric, and bronze alloy on an acoustic.
Plain strings are just a steel wire with plating on it-- usually nickel for an electric and bronze for an acoustic. Plain strings are easier to bend than wound strings which is why the G is usually plain on an electric.
Sometimes strings are 'coated'. The composition of the coating depends on the manufacturer, but generally it is a variation on a polymer or plastic. This coating helps to keep the dirt and grime of of your strings, and lets them last longer. Usually coated strings are more expensive than uncoated strings.
How Do I Know When To Change Strings?
Pay attention when your strings are new because the aging process happens so slowly you might not even notice. When strings are old, they lose their shine, can become somewhat sticky, and sound a little less bright and jangly than they did when they were new. You probably won't notice a huge difference until you put new ones on.
The amount of time needed between string changes varies with the individual. It really depends on your body type (and indirectly with things like diet, fitness, composition, etc.). If your skin is acidic and oily, you will go through strings quicker. If you are dry, fit and consistently clean-handed, your strings will last a long time. It could be a matter of weeks or months. If you are a nashville player, you might change strings as frequently as every couple of hours.
How Can I Take Care of My Strings?
There are a couple of things you can do to maintain your strings so they last as long as possible. Most importantly, wash your hands before you play and wipe down the strings with a clean polishing cloth after you play. There are also string conditioner compounds that will help fight dirt, grime, Minnesota elements, and string-to-finger friction. Also, keep your guitar covered when not in use so that dust doesn't settle on it, and take care of your own body too. If you're desperate, you can boil your strings like Eddie Van Halen to make them last longer.
How Do I Know What Is Best For Me?
Like a lot of guitar products, the best way to know is to play it and/or experience it. The marketers want you to believe that all you have to do is buy the product your guitar idols use, but that's a stretch. Make a note of the players you like and what they're using, but don't forget to try it for yourself and put it through a somewhat organized evaluation process. For the best idea, record yourself to audio or video and review it, and also check out the documentation of other guitar players on places like YouTube or more independent record labels.
Tired of the guitar store not carrying your favorite brand? This is my go-to website for buying that special set of guitar strings, especially in bulk.