At 21, Lily Mandelbaum -- co-founder of the style blog StyleLikeU -- is the youngest author at PowerHouse Books publishing company.

The inspiration for her new tome -- named after the blog -- came in the form of a scrapbook Mandelbaum lovingly made for her own collection. Looking for a tangible way to preserve the style moments captured on her site, she started an informal, bound chronicle of StyleLikeU's tribe of muses. The result became what we are celebrating tonight at a Vanity Fair-sponsored launch party -- a 224-page, PowerHouse-published volume crammed with more than 300 inspirational pictures.

StyleList caught up with Mandelbaum and her mother and co-founder, Elisa Goodkind, on the eve of their book launch.

WATCH: StyleLikeU's Founders On The Joy And The Fun Of Getting Dressed from StyleLikeU on Vimeo.

Stay tuned for further coverage including tonight's party.