I feel that users should spend a few mins each month making themselves aware of changes made to IRC. Server admins spend countless hours providing IRC related information (my server has one of the 'Net's biggest IRC help sites) yet few take the small amount of time required to 'brush up'.
I can appreciate that some people are not computer-literate whilst others know just about everything, I consider myself about 2/3 the way up the scale, an average user, however when need be I make the effort to read things and if I already know it then so be it.
Owners of channel websites could lend a hand here too - instead of linking to every mIRC script known to modern man and running forums for chatters to let steam off at each other they could provide either some advice relating to commonly asked questions or links to the same.
The room topic is another useful tool. The founder could dvertise the server's IRC info site there or an instruction on the most common question EG: /umode -m or M to msg someone, as per Webnet's #Webchat channel.
One last thing - room hosts should be prepared to help, most are bone lazy and want the @ so they can feel big and tough and often go to extra lengths to get it. Bear in mind that I'm not saing this applies to you or indeed anyone in particular, it's just an observation that is painfully obvious in the IRC fraternity the world over. My way around the repetitive typing is to make help popups and the script I give to other hosts contains about two-dozen of them. Those who prefer aliases over popups could well do it that way.
The reason why usermodes like +M and +m is because of the rampant levels of personal abuse and unsolicited advertising on IRC. Having said that I support the use of such modes. In the long run it makes IRC a pleasant place for more people.
