Online Database
The Gatherer Online Database is an excellent resource for players of this game. The database allows players to search for any part of a card, including names, phrases, numbers and words. You can also browse through different card types. Using this database is an excellent way to see which cards are available and which cards are best combined with the ones you currently have.
Sideboarding
Magic tournaments require players to win two out of three games. During official Magic tournament games, players may only use one of their constructed decks. However, they are permitted to keep a sideboard, a collection of cards the player may add to his deck for the second or third games. The purpose of the sideboard is to allow a player to adapt to the contents of his deck as well as his strategy.
Instants
Central to the game of Magic is the order in which cards may be played. Some spells, when cast, do not "resolve" right away. Rather, there is a period between the spell being cast and the spell taking effect in which an opponent may play an "instant" to counter the effect of the spell. If an instant is played during this period, the effects of the instant take precedence over the effects of the original spell. This is an effective way to avoid dangerous spells and should be used by any seasoned Magic player.