I agree with all of what MartynK said.
I went to Rome last July, and am hopefully going again this July. I went to Ostia Antica too and found it a fascinating place, though I didn't get many good pics. :shrug: It was bigger than I thought it was though, and it's very easy to get to.
I always buy a Travel Pass wherever I go abroad. Rome can be walked, but if you end up far from where you're staying at the end of the day, getting a bus back is very handy.
The buses only tend to get really packed at rush hour, but are very regular. I didn't use the metro that often, and at rush hour it is extremely busy.
If you want to go to St Peter's Basilica, get there early in the morning. I went about 8.30ish, and went straight in. After a look around I got the lift up to the base of the Cupola (dome), an extra 1 but worth it.
The climb up the Cupola is harder than you would think, but worth it to see the inside of the cupola close up, and for the 360 degree views of the city from the top. I wish I'd videoed the accent up the dome, as the walls get very 'fun fair
' as the walls of the dome start to curve near the top.
Got a video coming down, but going up would have been better. When I came out at about 10.30am, the queue was a 360 degree loop of the square.
I also went to
EUR to see the 'Square Colosseum', the Palazzo della Civiltà Italiana. And also to see the Museo della Civiltà Romana (the Museum of the Roman Civilization). There is a huge model of Ancient Rome in the museum to 1/250th scale and also a complete cast of
Trajan's Column which was just amazing. If going to the Museum though, check first for opening times, as they have some funny opening times, shutting quite early.
Don't shoot the coliseum at night, you just end up with immigrants selling tripods and flashlights in your shot! It's better to go in the day and shoot the tourists instead as there are hundreds and hundreds of them!
I don't agree with not getting pics of the Colosseum at night, you can get some very nice images with the traffic passing by. There is a little raised platform facing the Colosseum beside the Forum which is a very good vantage point.
There's one of the Colosseum in this thread of
my visit to Rome last year. This picture was taken on the Metro Station facing the Colosseum.
If you want some great architectural shots of the coliseum, take plenty of heavy ND filters and shoot long exposures in the day, that way all the tourists fade like ghosts and you won't be disappointed!
I'm going to try this in and around the Pantheon. It's my favourite building in Rome, and somewhere I like to visit a few times during my stay to try and get 'the' picture.