[X-Newbies] Importing Address Books

[Clive Read]

I have used Entourage, Thunderbird and Mail as my eMail client and  
have addresses in 6 regional address books in Thunderbird, that I need  
to import into MAIL, so that I do not have to create all the addresses  
again manually.

I exported the content of each address book in csv format to the  
desktop, but still cannot find the route to import them into 'Mail'.  
Wherever I look I see references to 'scripts' - which I do not  
understand.

I'd be grateful for help and advice.

Clive (in Spain) MacBook with 10.5.7