Catch the Circumvesuviana train, on the lower level of the main train station in Naples. This is reputedly a place where pickpocketing is likely, so be careful.
It took about a half hour to get to Pompeii Scavi on the train, which stopped at every stop along the way.
We arrived in Pompeii and entered using our Art Card. Be careful to ge in the right line if you have the card, it's the GROUP line.
I think the regular entrance fee was 14 or so Euro. If you don't have the Arte Card, go in the regular line.
Pompeii disappeared on August 24, 79 AD when Mt. Vesuvius erupted and spewed hot rocks and mostly ash all over the coast of the gulf of Napoli for miles. Fewer people were killed than was once thought, since an earlier earthquake did scare some folks out of the area, but it was still a natural disaster of horrific proportions. Because of the nature of the ash that enveloped everything, much of the town was preserved extraordinarily well, and it is a huge education in what life was like in the Roman Empire around the time of Christ and the early Christian church.
Once you get there, there is a huge amount of interesting stuff to see. You have a very long day ahead of you. I recommend highly against the tour. They provide a small tour book and a good map; you can also usually buy a more involved tour book. But use them and lead yourself around. You will find that the tours do a smallish set of places which are overrun with folks when they are there, on your own you can explore. Don't worry about getting to THE baker, there are a dozen bakers, some better, etc. So find your own way around, especially if you have the day.
Some of the highlights for me were the Forum area, which was very interesting, some of the houses with existing murals, the mosaic floors, especially the "Beware of Dog" floor (very very cool) and the very elaborate large floor with many small patterns (including a woman's silhouette) on the Via Abondanza, the theatre quarter and the hose of Venus, with the wonderful large mural of Venus. IN the necropolis, the large circular benches built to memorialize women was neat, too. It was clear this was a culture in which women were active. It was a very full day.
The weather was incredible, with blue skies and few clouds, even over Vesuvius. We got some wonderful pics with all the light.