I still don't see where to DELETE or even add names to established group folders.

Question

i have just downloaded thunderbird and imported my address book. i want to delete some old group folders and add some names to other old group folders. all the options to delete are greyed out.
when trying to add a name to a group, i can add it and click ok, but when i go back to it, it isn't there.
also, a new group i put together is stored under the "personal address book", but will not save into a new group. the folder shows up - twice in fact under the "Mac OSX Address book" with no addresses in either of them...AND, i can't delete them or a few old groups that i no longer want.
i am a newbie and not that computer savvy, so please no complicated techy instructions. i'd rather you just shoot me.

Answer 1

For a long time, Thunderbird has had read-only access to the mac address book. ISTR reading that this has changed recently, but as a non-mac user, I can't check for myself. "Read only" means that Thunderbird can't modify the mac address book.
However, you ''should'' be able to store Mailing Lists in the Personal Address Book. If in general you can't make any changes to an address book, that might indicate the underlying data file is corrupted. The usual way to repair it is to export its contents to an LDIF file, delete the original broken address book, then re-create it by importing from the LDIF file.
Since the Personal Address Book and Collected Addresses are "special" and hard-coded, you won't be allowed to delete them. To remove either of these, you need to locate your profile folder, close Thunderbird and delete abook.mab for Personal Address Book, and history.mab for Collected Addresses.