No matter how many times you look at pictures it's still not quite the same as seeing this historic place in person. As you walk through the ruins you can really put yourself in the place of the people who lived there. Little boxed areas that would of been peoples homes and shops with a clear view of Mount Vesuvius.
The ruins are huge! I would take a few days to get through them all but I spent about 3 hours and got a good amount of coverage and easily enough to really appreciate the area.
After walking around the ruins we caught the city buss up to Mount Vesuvius. It was 5.40 euro there and back per person. Vehicles are only allowed to go to a certain point up the mountain and from there its about a 20min walk to the top with no stops. It's not hard but it is a bit of a workout if you aren't used to hiking. Then again, we saw people with strollers and elderly people heading up so it really is do-able. Anyone with physical disabilities may have issues getting to the top however, it is quite sandy so not much grip for wheelchairs but we did see a small car go up so I'm sure (for a price) there is an option for someone to drive you up if that works better.
Tip: There are many entrances to the ruins, some tickets will only allow you to enter from a certain entrance so make sure you check what entrance is on your ticket.
See pictures from Mount Vesuvius here. See pictures from Pompeii here.