First things first: if you have a custom map, you should make sure that all gametypes supported by your map have their abbreviation listed in your map's .arena file. If you forget to add the gametype abbreviation to the "type" entry of your .arena file, or forget your .arena file altogether, then users will not be able to select your map from their in-game map list for that gametype. (They can still start your map with the console map command, however.) Your .arena file should have the same name as your .bsp file. (ie: if your map is named "bobshouse.bsp", your arena file should be "bobshouse.arena") The contents of your .arena file should look like this example from mp_shop.arena:
{ map "mp_shop" longname "The Shop Under Siege" type "dm tdm elim inf" }
The opening and closing braces are necessary! "map" should be the same as your .bsp file name. "longname" will be the name displayed for your map in the in-game map list. "type" is a list of the abbreviations of supported gametypes, separated by spaces. The standard Raven gametype abbreviations are:
dm - Deathmatch tdm - Team Deathmatch elim - Elimination inf - Infiltration ctf - Capture the Flag
(Abbreviations for gametypes will be listed with their entity\trigger profiles.)