Playing games online is a great way to learn the rules of the games. The payouts and odds can be complicated on some games.
Craps is probably the most intimidating for new players. Sci Bo and roulette also offer high payouts on some bets and are less complicated.
Learning to play Blackjack “by the book” reduces the house edge but if you want an advantage you’ll have to learn to count cards. I would not recommend trying it live until you’ve practiced to the point of being able to carry on a conversation while maintaining an accurate count.
The last place that you would want to be seen as a new player is on the poker table. Every time I play poker I see someone who thinks they know the game but reveal that they are new by not knowing situational etiquette. Some new players bet too high with premium hands, for the level of the game. Others will take too long making simple decisions. They think that it makes them look smart and experienced because they saw it on T.V.. To a regular player such actions are “blood in the water”. The best way to learn is to play online to get the rules down and then play live at a low level - quietly watch to betting levels and general ease of the experienced players - Never fall into the trap of criticizing others play. If some made a dumb play, remember it, use the knowledge when the time comes.
You can learn more about betting systems and money management at http://www.gamblingandcasinoguide.com