This is an idea that I have passed on to several people, and all of them have believed it would greatly help.
Raid Bulletin Boards Intro:
Raid Bulletin Boards would be where the starter of a raid could post that he has an upcoming raid.
Raid Bulletin Boards Functions:
1. The Raid Bulletin Board would allow the poster to chose the time and date for his/her upcoming raid.
2. The Raid Bulletin Board would have a system for the raider looking for a raid to select the dungeon he/she wishes to raid, and it would narrow the search down to the people who need that certain raiders class in their raid. There would also be a gear checker, which would check to see if the certain persons gear was good enough for that certain raid (The poster could preset a req. amount of stats and what-not for the certain classes, and if they wished to be picky they could narrow it down to spec as well. Making sure that everything was in line).
3. The Bulletin Board would allow raiders to place themselves down on a listing board where someone looking to start a raid could select players they wish to accompany them on their raid. In this listing it would detail exactly where the raider wishes to go, along with what pieces of gear they wish to acquire. Making gear distribution simpler as well, as this would let the raid leader distinguish who needs what, and who doesn't.
4. The same as in a raid, there would be a status screen for each posters upcoming raid, with a listed amount of each class, and how many are needed. Such as 2/6 Rogue Slots Filled, this would make hiring much simpler, since each amount of the particular class would be clearly listed.
5. As far as the notification goes (As in when someone applies for a spot in a raid, or if the poster is requesting that someone joins their raid) there could be a little automated message saying, " ???? has requested for you to come/invite him/her on your selected dungeon raid." There would then be a new selection where Whisper, Target, and Ignore lie which would say Join/Invite to Raid.
6.The overall function of my idea, is to simplify and quicken raid hiring/joining for all of the Warcraft players.
I use RaidNinja http://raidninja.com/ for scheduling my raids. This ties into many bulletin boards available, though this does not have an in game invite/calendar addon. I just use oRA2 /rakw to do invites, done.