For Pompeii you take the local Circumvesuviana train (2-3€-30minutes) from Sorrento and get off at Pompeii Scavi or Ercolano (a few minutes from Pompeii) for Herculaneum. The entrance to Pompeii is just across the street from the station. You can either hire a guide there or rent their audio guide. Same for Herculaneum except it's a couple of blocks down the street from the Ercolano station. You can buy a combo ticket for 20€ which gets you into both sites.
http://www.pompeiisites.org/Sezione.jsp?idSezione=1726

For Capri, catch the ferry or hydrofoil at Sorrento's port. From Capri's port, take either the funicular, bus, boat (depending on which you want to see first). Be sure to get a return ticket to Sorrento. Water transport does not run late (until 7 or so) and you don't want to miss the last boat.

Capri has bus service to most of the island. One of our favorite things to do was ride the chair lift from Anacapri to the top of Mt. Solaro. Pass on the Blue Grotto if it's not a clear, sunny day.

We stayed 8 nights in Sorrento and used it as a base for day trips. As mentioned above, Pompeii is very easy - a half hour commuter train ride. You can also go to Naples for a day trip - same train - it's another half hour. Lots of people do both on the same day but we did one day for Pompeii and another for Naples (and then we took the boat back to Sorrento).

There are several boats (ferries, hydroofoils) a day to Capri. There are also 'tours' to Capri. Smaller boats, many of which also do tours around Capri. But if you take a public ferry/hydrofoil from Sorrento once you get to Capri there will be people in the harbor selling 'boat tours' to the Blue Grotto and around the island.

You don't mention Amalfi, Positano? Are you going there before or after Sorrento? That's what most people do, but we did them as day trips from Sorrento. We wanted to stay in one place for the entire 8 days.

Here is my trip report - I describe how we got to places
http://www.fodors.com/community/europe/amalfi-coast-rome-and-croatia-images-of-three-hot-but-wonderful-weeks.cfm

Photos - http://www.pbase.com/annforcier/italy_amalfi_coast_capri_naples__pompeii

I have done day trips from Sorrento to Capri, Ischia, Pompeii, Ercolo, Mt Vesuvius and the Amalfi Coast by boat, bus or train and it is very very easy to do on your own - once on Capri you can take a boat from the port to the famous Blue Grotto and can use buses to get around the island or take some nice walking routes.

Blue Grotto subject to being closed in high tides so if that is a focal point plan accordingly.

Hi guys - thanks very much for the input. Once again I think joining this forum was the smartest travel move I've ever made.

Isabel, thanks very much for all your info. I look forward to reading your trip report. Now, regarding Amalfi ...

A long time ago when I was 21, I was on one of the under-25 bus tours and we did all of the Campania region. The Amalfi coast is the main reason I want to return there - to show my wife what an incredible place on earth it is! However, I swore back then that I would NEVER again tour the Amalfi coast from a bus seat - waaayy to close to the edge for my liking. Anyway, this is the one sightseeing tour that we have splurged on. We have a private driver taking us to Positano, Praiano, Amalfi, Ravello and Salerno - all in the air-conditioned comfort of a Mercedes.

And the over-indulgence of this tour is one of the reasons we wanted to see the rest of Sorrento's highlights independently. We also have a few more "spare" days in Sorrento so can see more of what we enjoyed most.

Thanks again for all your help and URLs.

Regards,

Steve

Isabel - Hello again.

Thanks for the great trip report - it was very helpful. And I have to join the throng of posters who enjoyed your photos. You obviously take your photography seriously.

Earlier, I mentioned one of the main reasons I wanted to come back to Campania was for the Amalfi Coast. Well, another great memory I have from those carefree days - 21 years old, 18 months in Europe and my only responsibility was to come up with the next destination on the continent (I was based in England) - was the Blue Grotto.

The way you described it is exactly the way I felt about it. I'm not sure if the colour of the water could be accurately captured in those days though. I thought it would have to be one of those experiences that could only be committed to memory, but your photo is excellent. Thanks for reminding me how great that experience was.

I noticed you didn't elaborate on the Green or the White Grotto (I, too, have never heard of them). Does that mean that they are not worth the effort?

Regards,

Steve

Isabel, that's a wonderful collection of photos - and it's good to find another PBase member here!

I hadn't seen either those or your Trip Report before, so thanks for giving them a mention - although I have to note one glaring omission from your itinerary... Ischia next time, perhaps?

Peter

Steve - Yeah, I still sometimes just sit and watch my few minute video of the blue grotto, it was so cool. The green and white grottos you can see from the bigger boat, they aren't all that enclosed like the blue grotto. The green one really did have green water but the white one was just a cave/grotto area that you could look into. There were a few people swimming in there if I remember. There is also the emerald grotto back on the mainland, near Positano. We considered doing that one but most of the reviews I read here said it was not worth while.

Peter - I've read many of your posts and found them very helpful. Definitely want to go to Ischia and I do love that area so am planning another trip there hopefully in a few years. Next summer we are planning on going back to Italy but more northern areas. I was actually just about to buy the plane tickets but am a little concerned about the economic situation. Do you live there full time? What is your take on likely impact for tourists.

Hi there - and thank you! Yes, so much Italy, so many places to see - and never enough time?

We've been here since March 2003, just popping back to the UK occasionally for visits to family and friends.

Only wish I COULD forecast what's going to happen! I guess the Euro might fall against stronger currencies, if only there were any? For all of the recent antics, it's odd how relatively little the value has moved against either of ours:

http://www.pbase.com/isolaverde/image/139537211

In some parts of the country this has been a bad year for visitor numbers - with good offers at the last minute - yet other places (especially the most popular cities) appear to have been doing well, and the official figures show that over the summer hotels managed to fill more of their rooms than last year, at whatever price they got:

http://www.pbase.com/isolaverde/image/140094178

Perhaps worse is yet to come.. but let's hope not!

Peter

Isabel - sounds like you get to Europe quite often, you lucky things! Unfortunately for us, it is a LOOONG way from Australia so we tend to travel to Europe less often, so need to stay for a longer period.

We start in April, 2012 spending four weeks visiting Amsterdam, Paris and Switzerland and then finishing off with a further 4 weeks in Italy. So like you, we have built in a number of "nothing" days to recharge our batteries. I think 8 weeks is going to be a little tiring but worth it! We are starting our Italian vacation in Bellagio on Lake Como and working our way down to Sorrento.

BTW, I have saved all of the Pompeii links you provided and will study up before we get there. I have noticed that many other posters say they prefer Herculaneum to Pompeii. Did you have a chance to research there?

Peter - thank you for joining in. I have started to read a few of your posts regarding Campania and also found them very helpful - and having photo support makes navigating the area so much easier.

Regards,

Steve