Tag offer

The question is - no one thought about creating some kind of help in tagging? I mean, when you add a tag you don’t even guess there is one or not, but in order to know you need to check. And what if you make a drop-down list of tags, at the end of which a comma is added? IMHO diminish the creation of new tags on the order (for example - what) tag postait for the topic, which refers to Habr? habr? habrahabr? or the same, but with ".ru"? Or or even write in Russian?

ps It seems to me that this will be useful especially for beginners, although it will also be useful for “veterans”.