What type of resources should I consider for an initial city?
Solution 1:
Your first city in a region is likely most difficult to get started since you can't get any free help in the form of Fire, Police, Health and Garbage services from neighbors. You're going to have to build these items yourself.
To mitigate, give yourself a break on power generation. You first city should have abundant oil, coal or wind (and wind is a very distant third choice) to use in your primary respective power generator. This way you won't have to purchase power-generating raw materials on the global market, an expense which can quickly become a burden to a young city. If you're lucky enough to have quite a bit of your resources available, you can even sell the extra on the global market with a trade depot. Give up on the ideal of a clean power first city unless you want extra headache.
In addition, tourism and casino income is an easy first city moneymaker. Plop it early and add a police station nearby to handle any additional crime it generates. If you've got water or rail in your region, connect those up so you can get more tourists. Casinos are a great way to get a good deal of early money.
Solution 2:
Consider the wind, if you generate pollution it helps to site so that the pollution blows out, preferably not to another city. Be patient and build your capital. I always start with wind even if I have other resources. Then water and sewage plants, again paying attention to the wind. Next is education. The better educated the sim the less of everything it will need. Once you have enough capital you can then specialize and have enough money if things don't go well at first. Be careful about placing intersections too close to your entrance. Dump the wind after you get started, it takes up too much space.
Solution 3:
Oil and Wind are also good. Having the ability to transport and refine oil is also good income. Plus being quite flat is also quite nice ;)
Solution 4:
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.