Choose a good, fast host. Where possible take a trial and see how it goes before signing up properly only to find that the connection is terrible for playing online games. Some gaming services offer their own exclusive connections purely for use on their game services, these usually offer you the best connection possible. The Game Well, if you want to play online you will need the game. If you want to play some of the popular games such as Half-Life, Quake 3 Arena and Unreal Tournament you will have to buy the game in order to play it.
All game developers release patches that fix problems and add changes to the game to improve it.
All game servers will require you to have your game patched to the latest version before you can play. If it is not patched then you are unlikely to be able to play. Patches can be downloaded form a lot of places. Many games such as Half-Life and Quake 3 Arena also have mods, short for modifications. These are usually created by other people and act as add-ons to the game, many add new styles of game play, new weapons and maps.