I would start while still on the ground and bring up MAP Mfd. Target moon. Then visualize the launch direction such that your orbit would cross the moon's orbit about 45 degrees east of the current moon position in MAP. (explained more below) It's not too critical, anything from 30 degrees to 60 degrees could work, but shoot for 45 degrees. What this does is estimate about 45 degrees of moon orbit, or 1/8th of its orbit or about 3.5 days till the moon gets to the same place that you will be arriving out near the moon's orbit.
When I say visualize the launch direction, it's actually fairly easy. If you've ever flown in complete circle in the atmosphere with Map up you can see your orbital path change from quite sinusoidal when high latitudes are not too far from the equator, to a square wave when your path crosses the poles and back to sinusoidal. So knowing what the wave probably looks like, imagine a wave that crosses both your current position on the ground and the point on the moon's orbit where the moon will be 3 or 4 days from now.
Then once in orbit, TransX will allow an easy offplane transfer using a TransX maneuver. Start the maneuver planning with about 3150 m/s deltaV and then adjust both date and prograde to hit the moon. With more practice and precision you might even be able to arrive at a specific orbit around the moon with minimal midcourse corrections.
