What is the best way to get around Barcelona, Sitges, and Coma-ruga?

The best way to get around Barcelona is by public transport. You can get this T-10 card of 1 zone for Barcelona. To go to Sitges and Coma-Ruga there are RENFE trains from Barcelona,but I think you need a card of 2 zones. If you have a bike, Barcelona has a lot of bike lanes all over the city. It's a good way to get around Sitges and Coma-ruga, too.

In my experience, those city cards are NOT worth it. You might find it's different for you. I don't know what a t-10 card is? Is that the 10 metro tickets? Those are worth it...you can combine it...buy ten, and use three each or whatever. Trains are simple and inexpensive. I'm not positive (You can go to the Renfe site and get ticket prices) but I think Barça - Stiges is less than 5€. It's very easy to get around. If you have no experience with metros, you'll figure it out in about a day, max. They are simple the world over. You can use that to get into town from the airport, depending on how far your hotel is from the metro stop. Taxis are pretty expensive, but worth it if you have a bunch of luggage, or if your hotel is far from the metro stops.