As there are quite a few different ircd/services packs out there its going to be pretty difficult to give you what modes/definitions you need, as some do things different and thats not thinking of the custom networks out there. So with that in mind may I suggest joining your network help channel where I am sure a friendly ircop would tell you in a heartbeat.
Good luck
Agreed. Though here are a couple to get you started:
+k password = set a password key for the channel so only those who know it can enter.
+m = moderate the channel so only those who are a voice or higher can speak.
+b nick/host = ban someone.
+n = no external messages so people have to be in the channel to message the channel.
+t = only ops can change the topic.
+r (or maybe it's +R) = only people who have registered nicks can enter the channel.
Those are usually the same from network to network, but there may be some out there that are different. As mentioned, the #help channel is a great place to start.
+l = limit (sets max user limit for channel)
+p = private (channel is not visible in /whois but visible in /who) and is "obsolete"
so people rather use +s = secret, which hides channel in /whois and /who (but not from opers, just from regular users)
as noone told you how to use "room" modes:
/mode #channel_name +/-mode
example: /mode #mirc +s
+ sets mode
- unsets mode
if it is channel mode for user/host (ban, op, halfop, voice or userop)
then it is /mode #channel mode user/host
--- ban example ----
example: /mode #mirc +b *!*@stupid.spammer.com
or /mode #mirc +b idiot
--- op example ---
/mode #mirc +o my_friend
for multiple ops or voices or whatever...
use /mode #channel +ooo nick1 nick2 nick3
(depends how many modes = how many users)
you can also combine modes :P
/mode #mirc +stn-cl
which sets "stn" modes ON and unsets "cl" modes OFF
:P