I have used online sites for years, to book everything from airfares, hotels, car rentals and Italian overnight ferry tickets. I have never had any problems, but I would suggest that you check many sites before you purchase. Sometimes you can get better deals through the hotel or airline directly, than with an online service. I also use travelaxe, a free service which checks a number of online sites and shows you the prices for hotels, airfare and car rentals: http://www.travelaxe.com/

Good luck, Penny in Toronto