The standard electric string type, and the best beginner choice, are round-wound, nickel-plated steel strings. Round-wound strings are used for all popular playing styles. Nickel plating helps prolong string life and adds the brightness to the string's electric tone. You may encounter "flat-wound" strings, but these are not usually offered in light string gauges and are used primarily by jazz guitarists.
Ultra-light gauge electric guitar strings are the best strings for beginners, as they produce much less tension than thicker gauges. Ultra-light sets are also identified by the high "E" string gauge, which is .008, with the rest of the string matched in gauges that are complementary to the high "E." Asking for a "set of 8s for electric guitar" is the common jargon at music stores.
Extra-light gauge electric guitar strings are the next best beginner string, as ultra-light strings may feel to loose for some players. Extra-light strings are identified by the high "E" string gauge, which is .009, with the other strings also matched in gauges that compliment the extra-light set. Asking for a "set of 9s for electric guitar" at the music store will procure an extra-light string set.
When a string breaks, it's not necessary to replace the entire set. The best replacement string will be one that is matched in gauge and brand with what is installed on your guitar. Save the string set package, as it will include a listing of string gauges included in the set. Bring the package to the music store or ask for the string by brand and gauge: "WYZ (brand) 15 (gauge) string, please." In the case of a single "G" strings (third string) for electric guitar, some single strings of typical "G" string gauges are available round-wound or unwound. Check the string envelope before purchase or specify "unwound," as plain "G" strings are the best type for beginners and the standard string type used in sets.
Several electric guitar string companies offer "coated strings," claiming longer string life, but they cost two to three times more than standard strings. These strings do prolong the string's tonal life by way of a special material that keeps dirt and oils from penetrating the metal but do not prolong the string's physical strength. Coated strings are best for beginners who do not break strings very often, but for those who do, the added cost may not be worth the investment. Coated strings are offered in all popular string sets, including extra and ultra-light.