OK, since i am fairly new to networking, here is my questions...
If i had a router, and the one interface was pointing to the ATM interface, what would be considered the ATM? Would it be the switch from the service provider or what?
If you have the option between an ATM and ethernet uplink for a simple CPE, the only reason to choose ATM is if you are supporting something fancy like interleaved VBR priority traffic, VoATM, or multiple VCs to different edge routers or devices. Odds are you don't need to do this, so connect to the ethernet port.
If you have no CPE and must choose between ATM and frame or IP T1 lines, then you might want to consider ATM for the low latency cell-based multiplexing to scale past 1xT1, but only if you can find the IMA interfaces cheap and the provider actually supports IMA.
ATM would have been better accepted if the interfaces had not been so expensive (it has an awesome feature set), but these days it is a more or less a dead technology outside the provider backbone where there are people who actually value its features enough to learn how to use it.