Rick Steve's - As I said in my Venice post, this will be our main guidebook for our Italy travels. We will use the walks, museum guides and basic phone number and other essential travel information. For the most part I have copied the important info on opening times, prices, metro stops, address, and other info into my Moleskine, but will bring this for reference. There wasn't much information on his website to link to, but its worth picking up a copy of his guidebook. I wouldn't buy seperate ones for each Italian city (Venice, Rome, Florence, etc.), just buy the Italy guidebook, it contains much the same information and takes up less space than multiples.
I love the Frommer's maps for Rome webpage. I printed out a bunch of them and pasted them in my Moleskine. It's my own little DIY guidebook, with all of our hotel reservation stuff in it, photos of the outside of our hotel rooms (so if its late at night we'll be sure to recognize it rather than walking past looking for the address) and a bunch of Frommer's maps. It's much easier to print their guidebook maps than to try photocopying out of our Rick Steve's guidebook.
Rome Airport Guide (FCO): Airport layout, maps, trains and buses from Rome Airport FCO to Rome or other areas in Italy, where to meet at Rome Airport.
Summer in Italy - Transport Strikes: list of current transportation strikes (rail, airports, etc.)
Where to Stay:
I would start with a decent guidebook which will give you an idea of how much you can see during the amount of time you have and a fairly good order to put it all in. For online help I like the Frommers Attractions and Itineraries pages. They have good descriptions, pricing and hours all in one place. I would still double-check with specific attraction's websites where possible.
Vatican Museums- You cannot buy reserved tickets for the Vatican museums (Sistine Chapel) to bypass the lines. The only way to avoid the lines, is to book a tour. I heard that booking directly with the Vatican is impossible and books up more than a year in advance. I e-mailed them just to check and was pleasantly surprised to have an e-mail waiting for me the next day confirming our tour with the official Vatican docents. No line for us, yay! For information on the Vatican, check out http://www.vatican.va/.
Borghese Gallery in Rome You have to have reservations for the Borghese Gallery. You can buy these through their website.
http://www.mmdtkw.org/: Lots of general Rome information, most recently updated in 2000. http://www.romaturismo.com/v2/en/main.asp (official site of the Rome Tourism Board) http://www.tickitaly.com/ (Italy's site for buying tickets in advance and avoiding lines)
Enjoy Rome, Via Marghera 88, near the train station (tel. 06-4451843), was begun by an English-speaking couple, Fulvia and Pierluigi. They dispense information about almost everything in Rome and are far more pleasant and organized than the Board of Tourism. They'll also help you find a hotel room, with no service charge (in anything from a hostel to a three-star hotel). Summer hours are Monday to Friday 8:30am to 7pm, and Saturday 8:30am to 2pm; winter hours are Monday to Friday 9am to 6pm, and Saturday 9am to 2pm.