Coal, Oil, Ore along with Trading will make you the most amount of money in your initial city due to reliability of global trade. This city will need to be fully self sustaining (Water, Power, Garbage, Police, Health, Fire) and that will slow you down when you're not bringing in enough money from a town that only has Wind or Water as it's resource. Also, since this is your initial city it can be used to fund other cities.
I would advise against Casinos because at the moment Casinos can be very hit-or-miss financially because of their buggy nature. They start out fine but soon they tend to go into the red and you can't control it. Maxis is aware of the buggy nature of Casinos and hopefully it will be fixed soon:
If you really want to go Tourism and Casinos, it was recommended here that you should plop Casinos near your regional entrance.
I find the best strategy is actually to found a "starter" city in the region before the city you want to actually play a lot. In this starter city you should focus on regional-access upgrades like the Town Hall upgrades (so you don't have to pay for them in your true city), along with a bus terminal. The extra busses will migrate to your true city for free (once you build a bus terminal), thus saving you expenses there. Once you unlock enough things, start your new city and you will find it financially less burdensome along with ease from having buildings already unlocked. If for instance you are eyeing a city with loads of resources except water, build extra water buildings in another city and sell it to your resource-heavy city.
This, of course, is all down to your play style.