The house edge for roulette with zero and a double zero is indeed 5.26%. If you play a single zero wheel the house advantage drops to 2.7% which is much better, but it is still a suckers game. Playing the 0, 00, 1, 2, 3 combination pays only 6:1 and has a house advantage of almost 8%. Again adgp is correct. Stay away from roulette.
Even though I promote CRAPS you need to stay away from the center of the table; proposition bets (a bit complicated) and the hard ways (betting that the dice will be the same like 3 and 3 to make a "hard 6" (no giggling or snickering please). The best bets in the center have a house advantage of 5.56 and go down to more than 17% house advantage. All very much sucker bets.