While it may be strictly true in the U.S. that you don't need the copyright notice, that may not apply elsewhere. Also, as dws mentions, your intent isn't obvious. Is it open source content? Is it GNU licensed? etc... I now, after a painful education, believe taking obvious and constructive action to give notifications and actively protect intellectual property is a primary responsibility. Not that I didn't before, but it's certain that passive reliance on the good manners of others is unfortunately naive.

Allow no mirroring without explicit written permission. When unpermitted copying, mirroring or other major uses are detected, immediately ask for it to be removed. Cases of mis-representing or _not_ representing ownership / authorship should be acted on instantly. Not acting to protect can be a legal issue should it ever come up.

"... without restricting the availability of the information?" is handled by your publishing it on the web.

Not that legalities (or my or anyone else's intrepretations of them) need to be abused in this thread - but not acting in advance to advise others and obviously signal your intent, or not acting to correct/protect after the fact - can become a real problem.

I have read arguments that even other's linking to your site could become an issue for your over-achieving attorney. Not that I worry about being linked to, I like it and promote it, the more the better.

But copying, over-excerpting, excerpting without attribution, all those things can become annoying problems.

However, via a friendly copyright notice, maybe some explanation of how easily mirroring or copying can be achieved, can get you quite good results - plus some interesting contacts with those that are interested.

I don't mind anyone mirroring and using the information that I provide because that's why it's there

Is that really why it's there? For others to take at will? Or do you want to retain attribution and rights to a later course? Could it be possible that someone mirroring your site also publish it as their own? How would you prove the date of publication for the html, especially considering that the pages probably evolve.

Ultimately, my experiences aren't near as dire as my tone makes it sound, but they were very real. Publishing on the web is a truly wonderful thing, but because the access is so universal, publishers really can't assume anything about rights and possible rip-offs.

0.02