Apamea is located an hour north-west of the city of Hama, and about 2 hours south-west of Aleppo. It is best reached by private car, so whether one is staying in Aleppo or Hama, one must ask the hotel to arrange for a car and a driver. From either direction, the road is filled with other historic sights and ruins, so one could fill an entire day with a variety of things to see.
Apamea can be reached by microbus. I took a bus from Aleppo to Hama, which cost S£85 (There are also frequent buses from Damascus to Hama). Then I took a taxi to Hama's microbus station, which is on Sharia Salah-uh-din, about a 15-minute walk to the south-west of the city. From there I took a microbus to As Qeilibiya, which cost S£45 and took about 40 minutes. There you will find another microbus waiting to take you to Qa'alat al-Mudiq. This only costs S£10 and takes just 10 minutes. You can get dropped off on the main road, near the museum turn-off, which is to your right as you enter the town. Ask for al-mathaf (the museum). After you have visited the museum, turn right out and you have about a 15-minute walk uphill to the ruins. You will see the citadel up on the hill to your left, and the first site you will reach on your right is the theatre. From the theatre it is about another 5 minute-walk to the main ruins of Apamea.