I'm wondering how I should use respawn areas on my map. Specifically, should I set them as owned by a team? Should every part of the map be covered with them? Should they overlap? And should I use a couple large ones, or a lot of smaller ones? Sorry if that's a lot of questions, but I'm not very good with spawns. Help would be appreciated.
Give us an overview picture and then I will be able to help. Spawn areas can be complicated. There are some tutorials about spawn areas for Halo 3, but they should work the same way in Halo: reach.
If you want a respawn area to simply group an area so that spawn influences like teammates, enemies, and recent deaths, use a weak respawn zone left as the neutral team. Using a normal zone for that will allow both teams to spawn there in a team game. To assign sides to teams for CTF and such, use a normal respawn zone grouping all of that team's spawn points assigned to that team, set to the gametype or to no gametype if every gametype including Slayer is supposed to have side specific spawns. Alternately, if the shape of your map makes it easier, use an anti-respawn zone assigned to the red team placed on the blue side with the proper gametype label to allow the red team to spawn anywhere but inside that particular zone. You don't have to cover the whole map with respawn zones, but if you have any normal (not weak, not anti) respawn zones, the assigned team will not spawn anywhere outside of that zone. If it's a neutral normal respawn zone, neither team will spawn anywhere outside of that zone, so I highly recommend you make all of your neutral team zones weak zones.