Also i would like to ask what is the best site to book tickets to these attractions, i have noticed different prices in different websites..not sure why? i have friends who advised to book from the official website for each of these venues? Question is, are there official websites for each of these venues? Thanks

I am not going to Venice, so no help there.

For Florence I booked my Uffizi and Accademia tickets online. There is a fee to do this, but I am leaving today and wanted them quickly. Even with that, I could not access the tickets until the following day. I kept the link open and was able to get them that way. Of course go see the Duomo and some of the other churches. My favorite place in Florence is the Boboli Gardens. It's a nice way to have a bit of down time - not looking at churches!

For Rome - get a Roma pass at one of the TI places. It allows you into many places faster and also on public local transportation. The first two sites are free. Make sure you use it for the most expensive ones. Plan the Colosseum and another expensive site as your first visits since it automatically makes the first two free.

The forum might be another good spot to see (and it might be the next most expensive - hint - Roma Pass). We also plan to go out and see the Appian Way and the Catacombs

Vatican - you can get your tickets there the day you go. I read it gets a bit less crowded in the afternoon. I'm trying that this trip because it was mobbed in the morning the last time I went.

Have fun and be open to going where your heart wants to look.

In Florence visit the San Marco museum across the SM piazza from the Accademia to see Fra Angelico murals - lovely. Visit the Duomo and the Baptistry and the Museo del Opera del Duomo behind the church to see the original baptistry doors. They have been restored. Visit the Uffizi, the Accademia, Santa Croce, the Bargello, the Ponte Vecchio. Sit with coffee or wine in the Piazza della Signoria - great for people watching. See the Procession of the Magi at the Medici-Ricardi. Take a bus from Piazza San Marco to Fiesole for a fabulous view of Florence and a nice lunch.

Three days is such a short time for Florence but try to see all of the above and still leave plenty of time for gelato.

The best way to book is through the official websites as other sites mark up the price.

I doubt you would get the value of the Roma Pass with only three days in Rome and one spent at the Vatican (it's not valid for the Vatican).

For the Vatican, you can book guided tours of the museums or entrance only tickets. This will let you bypass the long ticket lines.
http://mv.vatican.va/3_EN/pages/MV_Home.html

The official booking for the Colosseum is Pierreci. Ticket is 12€ and includes the Forum and Palantine (good for two days). There is a small online booking fee. If you want to buy while there, avoid the lines by purchasing at the Palantine entrance instead of the Colosseum. Either one lets you bypass the long ticket line at the Colosseum.

The official site for the Uffizi and Accademia:
http://www.polomuseale.firenze.it/en/index.php

There will be a 4€ booking fee. Any sites with an exhibition (many will have exhibitions during high season) will charge an extra 3-4€.
http://www.polomuseale.firenze.it/en/index.php

To add to kybourbon's post;
"If you want to buy while there, avoid the lines by purchasing at the Palantine entrance instead of the Colosseum. Either one lets you bypass the long ticket line at the Colosseum."

Go to
www.capitolium.org/eng/fori/pianta.htm

See in the bottom right a vertical street 'Via San di Gregorio'.

To the left of the E in Gregorio is a small odd shaped inlet ()== that is the Palatine Hill's ticket entrance.

You can't miss the monumental entrance which was actually the 16thC portal entrance to the Farnese Gardens that once stood atop the Palatine Hill and was reassembled here.

Now you can either go back to the Colosseum (bypassing the line/queue) or visit the Palatine Hill.

If you decide to visit the Palatine then turn left after the ticket office and you have 2 choices;

Either walk straight up the incline on earthen steps supported by wood (like something you would see in a wooded park).

Or follow the more gentle S-like sloping path up to the top.

Either (tree shaded) route puts you at the 'Hippodrome/Stadium Gardens' at the corner of the Palatine which is a good place to start.
Regards, Walter

Excellent feedback guys, thanks for the comments. I will proceed and start the booking using the website you have mentioned above.

I have noticed no1 said anything about Venice Any good attractions there or anything to do?

Im wandering if there is any chance to get to a beach close to any of three cities we are visiting..your feedback would be appreciated

The Lido is a long, skinny, barrier-type island in the Venetian lagoon. It has a beach all along the far side, with public beaches at the two ends. And it's reachable by the vaporetto from Venice. (But don't stay there; you lose the unique experience of living in a town with no roads and no vehicular traffic: no cars, no trucks, just boats on the canals and pedestrians.)

Of course there are good attractions and things to do in Venice - why else are you going there?

The best thing about Venice is just wandering the small streets, the further from San Marco, the better, to lessen the tourist crowds.

Places that many of us enjoy in Venice: Basilica San Marco (don't miss the museum inside); Palazzo Ducale; the Accademia. for a start. Tons of other lovely churches.

For Venice you can book for the Doges Palace:

http://www.tickitaly.com/galleries/doges-palace-venice-tour.php

I suggest looking at the destinations section of this web site to get an idea of the sites in these three wonderful cities.

For Florence, this "Top 10)thread has a lot of good suggestions
http://www.fodors.com/community/europe/florence-top-10-list.cfm

Thanks guys, i will take all these comments and come back to you with our final itenary so you can review and tell us your feedback

One question, do you think we should purchase the tickets for the trains, metro etc online before going or? This is for the internal transportation and not between cities

You can't purchase tickets for the Rome/Florence city transportation online. I doubt you will use any transport in Florence.

Take the Vaporetto to Murano and just wander around, then go on to Burano and just wander around - allow half a day for this. (Or vice versa.) Getting lost in Venice is a pleasant thing to do, maybe except at the end of a day when you're exhausted.

Hi Guys, how can i book for Colosseum online?

Don't miss the Rialto Market in Venice. Go rather early in the morning.

one quick question, can we buy one day passes for the metro? if so can you buy them online?

Are the metro passes the same as the bus psses?

Given your short time in Rome, I'd get a hotel in the center and just walk around. You see so much as you walk, the odd Roman ruin, the shops where they sell church vestments, and so on. Vacation time spent on public transport is time wasted.