The best resource I've found for information on release schedules and such is this.
Questions about Ubuntu or Ubuntu installation are fine an AskUbuntu main.
Questions about AskUbuntu are for AskUbuntu meta.
Releases you find on the web are going to be off topic per the FAQ. Only official Ubuntu releases are supported (there is no 12.05). The numbering system has been explained before, but basically it's:
12.04, 12.04.1, 12.04.2, etc, etc, until it reaches EOL.
