It's right hand.

It's hard to break loose most likely because of the finer
than usual thread used on this bolt.

May need an extension on the pipe. You should only be using
1/2-inch drives or higher. Anything less than this, and
things get unsafe. One guy here argues for 3/4-inch drives,
and he has a point.

An impact wrench, rented if necessary, is something to
consider for this job. Or take it to your local mechanic,
throw on the rack, have him loosen, then re-snug for the
trip home, but not too tight.

Plenty of folks here have wondered if it's left hand. I am a
long time poster here and have had my own 91 Civic's crank
pulley bolt off many a time. After several years, it's
usually darn tight. But I manage with a 1/2-inch drive set
and about a five-foot pipe extension on the end of an
18-inch breaker bar. Pillow beneath in case I slip. About 90
degrees of windup may be required. This is not for the feint
of heart or those not safety-minded.

Glad you asked that. This is one of the very oldest of the FAQ entires.

http://www.tegger.com/hondafaq/cranktool/index.html

Basically what Elle said, plus more.