I don't see a subscribe link for Little Lithuania either. John Peters is a significant contributor there; perhaps he knows more. From the main Forum 54 page, you can sign up for a login and password, but I think that might be to start your own group? Or not! It just isn't clear.
For letters to Lithuania, I kind of use this template:
Name (I copy and paste from the internet phone book so all the symbols are included)
Street Address (again, copied from the phone book)
I am sorry I cannot write this letter in the Lithuanian language. I hope that you can understand English, or that you know someone who can translate. I found your name on the internet telephone directory.
My name is XXXXX and I am trying to find the family of my great-grandmother (or whatever relation) in Lithuania. Her name was XXXXXXXX. She was born XDateX in XXXX Village, XXXX Area, Lithuania. S/he came to the USA/UK in XDateX, and his/her last village before coming here was XXXXXX Village, XXXXX Area, Lithuania. When s/he came to America/UK, s/he lived in XXXXXXX. S/he married XXXXXXX in XDateX.
S/he had brothers and sisters named XXXXXX who also came to AmericaUK. His/her parents were XXXXXXX and XXXXXXX.
Do you know about your family history? Do you know if this is your family?
Thank you very much. I hope to hear your reply soon.