営 - MANAGE Your BARRACKS or They'll Catch On Fire

Readings & Meanings:

いとな（む）

エイ

manage, barracks

Common Usage:

営業中

営む

Examples:

ただいま営業中です。

彼の家は、代々酒屋を営んでいる。

Translations:

We're Open (sign on front of a store)

His house has been run as a sake store for generations and generations.

Radicals:

呂 (spine) was part of 官 (government, bureaucracy), which added a roof (宀) to a pictograph of a collection of objects (呂). Then, later, it was merged with (presumably) 火 on top.

Think of the light of torches lighting a collection of buildings, and then think of managing all of those buildings, and then you've got 営.

References:
http://www.kanjinetworks.com/knetwork/KUANG.html#KUANG20
http://www.thejapanesepage.com/kanji/kanji/u.htm