Russian Alphabet:"В" as in... Vladimir. Lenin, or Putin.

Russian Letter: 

The third letter of the  Russian alphabet is letter Вв - but watch it, despite looking almost identical to a certain letter of the English alphabet (or German, French, Spanish and many  other alphabets), this letter's sound is actually "V" - as in Vladimir (Putin, or Lenin

Russian Names:

Russian name Владимир, pronounced as "Vlah-DEE-meer" has a long history. Way before Putin or Lenin came along, back in the 9th century, a guy named Vladimir was the one to officially convert the pagan Eastern slavs to Christianity.

Rumor has it that he actually was leaning toward Islam... but as much as he like it's other provisions, he could not possibly expect his army - or the rest of the country - to quit drinking.  So he had to settle for the religion of the Greeks.

The diminutive for Владимир is Володя or Вова. If you are addressing a very young boy (toddler age), you can also call him Вовочка.  

Young Volodya Ulyanov,
years before he became Vladimir Lenin.
Source: Wikimedia Commons

However, I would advise you against using this variant when addressing anyone old enough to tell jokes: a boy named Вовочка is a character from a vastly popular (and for most part vulgar) joke series.

I doubt you want to address Mr. Putin as either Володя or Вова... Lenin, on the other hand, or rather his younger version, was known to all Soviet kids as Володя Ульянов (Volodya Ulyanov). 

The most common woman's name starting with the Russian letter В is probably Вика ("VEE-kah"), short for  Виктория ("Vik-TOH-ree-yah") and the best known Виктория is most likely the Nanny character form the Russian version of The Nanny sitcom. Here is an episode: