Playing around with Dialog Kit I've made a script to fill the most important fields in a font family at once in Fontlab. The program follows Karsten Lücke's recommendations about Font Metrics and Font Naming in his well known PDFs.
I'm sure several of you will point better methods or syntax

so thanks a lot in advance. I will try to improve the interface and the script in the future, but for the moment, this is all I can do. Thanks to Tal Leming and Paul van der Laan for the help.

Usage:
1- Open your fonts
2- Set the "Weight" in each font info and click the "Italic" checkbox (if the font is italic). If you want to use different font weight names to the ones available in the Fontlab menu, the script must be edited. The script will uncheck the boxes later (it does not make linking families)
3- Run the script, complete the required information and press "OK".
4- Go and check the font info in each font to see the changes.
Warning: Robofab and Dialog Kit must be installed.
(*) Note on font metrics:
The script will duplicate "Ascender" and "Descender" in the OS TypoAscender and OS TypoAscender fields. "WinAscent" and "WinDescent" will also be duplicated in the Hhea Ascender and Hhea Descender fields. TipoLineGap will be calculated automatically and LineGap will be set to zero. 
Download:
https://github.com/retypefoundry/BatchFontInfo
Comments
thanks for the macro, really dig it.
Have you tried out our "Font Family Naming" script for FontLab, we created together with Karsten? It’s a little bit more straight forward then your macro, but it’s definitely missing the nice GUI, you did. :-)
http://www.cape-arcona.com/news/download/ca_font_family_naming_b-zip/
I’m curious, why do I need to enter Ascender/Descender? Isn’t that something I already entered during the design process of the font?
–Thomas
Thanks, I am glad other designers find my script useful.
I was aware there were other scripts to deal with a family's Font Info/Metrics but as I am learning Python, I just wanted to do it by myself and in a way that fits ReType's workflow.
>> why do I need to enter Ascender/Descender? Isn’t that something I already entered
>> during the design process of the font?
The real design Ascenders/Descenders values are frequently not the identical to the values we enter in the Font Info and sometimes we decide to change them at the production stage. Also, when making webfonts it's necessary to alter the Ascenders / Descenders of the whole family to follow good webfont practices.
Ah, okay. Thanks.
@DaveCrossland:
Yes I will!
The script is several years old and I never found the time to do that, but it’s raining tomorrow, so I try to publish them under Github.
well, unfair to post another script here (sorry Ramiro), but Dave ask about... Here is ours, now on Github: https://github.com/CapeArconaTypeFoundry/FontFamilyNamingB